Nhận thức và tần suất tập luyện thể dục thể thao sau phẫu thuật ung thư vú

Một đề tài fulltext về chủ đề mới lạ: nhận thức và tập luyện thể dục sau phẫu thuật ung thư vú. Ung thư vú là dạng ung thư phổ biến nhất ở phụ nữ. Các bằng chứng khoa học cho thấy vận động thể lực có nhiều lợi ích về tâm lý và thể chất cho người sống sót sau phẫu thuật ung thư vú. Nghiên cứu có tổng cộng 121 bệnh nhân tham gia vào nghiên cứu. Kết quả cho thấy hầu hết bệnh nhân có nhận thức kém về tập luyện thể dục thể thao sau phẫu thuật ung thư vú. Trong vòng 7 ngày đầu sau phẫu thuật tỷ lệ tập luyện thể dục là 86,78%. Tỷ lệ tập luyện thể dục sau >= 6 tuần cũng rất cao. Nghiên cứu có trích dẫn Endnote đầy đủ là nguồn tài liệu tham khảo hay cho sinh viên ngành y.

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PERCEPTIONS AND PREVALENCE OF EXERCISES AMONG BREAST CANCER SURVIVORS AT ONCOLOGY HOSPITAL, HO CHI MINH CITY

研研研研 Mai Thi Minh Nguyet.

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PERCEPTIONS AND PREVALENCE OF EXERCISES AMONG BREAST CANCER SURVIVORS AT ONCOLOGY HOSPITAL, HO CHI MINH CITY

Graduate student: Mai Thi Minh Nguyet

Supervisor& Committee:

Professor: Shiow- Li Hwang

Meiho University Graduate Institute of Health care

Thesis

A thesis submitted to the Graduate Institute of Health Care of

Meiho University

In partial fulfillment of the requirement for the degree of

Master of Health Care

July 2014

Background: Breast cancer is the most common cancer among women both in the

developed and developing countries with an estimation of 521,817 deaths in 2012worldwide Scientific evidence showed that physical activity could have physiologicaland psychological benefits toward breast cancer survivors In Vietnam, breast cancer isalso the most common cancer among women across the country An existing problem

in breast cancer management in Vietnam is that a large amount of breast cancer casesare lately diagnosed and the rate of late diagnosis is up to 49.5% that predispose todifficulty in treatment regimens and reduced effectiveness of breast cancer treatment.Another concern comes from the fact that survivors after breast surgery do not receiveadequate health cares, especially those related to physical activity, to prevent therecurrence of breast cancer

Objective: The aim of the study was to describe perceptions on physical activity and

the prevalence of exercise performance after surgery among breast cancer survivors

Methods: The study was a cross-sectional study carried out in Oncology Hospital, Ho

Chi Minh city from January to February 2014 The Health Belief Model was applied

in the study to investigate the perceptions of patients The exercise performances ofpatients were recorded through three interval time after surgery including the firstseven days, first 6 weeks and beyond 6 weeks The significance of the results wasassessed by ANOVA test, t-test and Chi-Square test at p-value of 0.05 using SPSSversion 16

Results: There were a total of 121 patients enrolled in the study The mean age of allbreast cancer survivors was 52.75 ± 10.60 Most of patients had the level of educationwas secondary school or over The mean family income of participants was 4.15 ±3.71 (1-20)

In general, the proportion of patients perceived toward suggestion of performingexercises and barriers of performing exercises were not high Other perceptionincluding perceptions of possibility of recurrence of breast cancer, perceptions ofseverity of breast cancer, perceptions of social support reached at average level, whileperception of the benefits of performing exercises gained high level The resultsshowed that in three different phases after surgery, exercise performance among

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patients was surprising high In the first seven days, the rate of performing exerciseswas 86.78% In the same token, the rates in the 6 weeks and beyond six weeks wereconsiderable high (94.21% and 82.64%, respectively)

Age, education, and marital status had showed significant associations withexercises performance at the first 6 weeks In addition, perceptions of benefits ofexercises performance and the prevalence of exercises performance beyond 6 weekshad a statistical significance (p=0.03)

Conclusion: Most of aspects in the perceptive model had low percentage of patients

being aware of, except perceptions of benefits of exercise performance Patients hadhigh prevalence of performing exercises; however, types of recommended exercisesand sports were not abundant and patients did not receive the instructions from health-care workers, especially in the prolonged stage after surgery The data also showedthat perception of benefits of exercise performance had a strong relationship with theprevalence of exercising; therefore education or training on benefits of physicalactivity on preventing breast cancer was supposed to have positive impacts onprevalence of doing physical activity among breast cancer survivors

Key words: breast cancer, exercise, perceptions

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This thesis was carried out at Nguyen Tat Thanh University and MeihoUniversity under the guidance of my supervisor, Dr Shiow-li Hwang, and Dr Tsuey-Huang I would like to express my deep gratitude to my supervisor and otherprofessors who had spent their precious time to instruct and facilitate me complete thisthesis I would like to send my thanks to all authors of published works cited in thethesis for providing valuable resources and related knowledge during my studying

I would like to give my special thanks to the Director Board, Science Council,Ethical Council, doctors and nurses of the Oncology Hospital for their endlesssupports in helping me fufill the thesis My thanks also gave to officers of theInternational and Postgraduate Training Department of Nguyen Tat Thanh University,scientists from the Meiho University, and my classmates who had providedadministrative supports and encouragement during my studying

There is no success without supports, more or less or directly or indirectly, fromothers individuals From the beginning to the end of my studying, I had received lots

of concerns and supports from my best friends and colleagues With the gratefulnessfrom bottom of my heart, I would like to thank Mr Lam, Dr Cang, Dr Cu and healthcare staff of Oncology Department and Nursing Deparment of 30/4 Hospital I neverfoget what my best friends (Minh, Mai, Xuan and Nga) had done to me during hardworking days for data collection I would like to be grateful to participants in the studywho although suffered physical and mental pains as well as numerous concerns indaily life had spent their valuable time to provide important information those will beused to help other patients receive better health care All of those made a strongmotivation to me in completion of the study

Finally, my deep gratitude was sent to my beloved husband and two sons, myclose friends and colleagues who always encourage, concern and share many aspects

of life to me and those made myself more confident to finish my thesis

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Chapter 1 Introduction

1.1 Statement of this research

Breast cancer is the most common cancer among women both in the developedand developing countries (Ferlay et al., 2012) It is estimated that worldwide 521,817women died in 2012 due to breast cancer (Ferlay et al., 2012) Incidence rates varygreatly worldwide from 27 per 100,000 in Middle Africa and Eastern Asia to 96 inWestern Europe In most of developing regions the incidence rates are below 40 per100,000 (Ferlay et al., 2012) The lowest incidence rates are found in most Africancountries but here breast cancer incidence rates are also increasing Breast cancersurvival rates are also reported with a wide range from ≥ 80% in North America,Sweden and Japan to around 60% in middle-income countries and below 40% in low-income countries (Coleman, 2008)

Physical activity is an important contributor to health and the related outcome ofquality of life (Farrell, Braun, & Barlow, 2002) One health condition that appears tobenefit from a physically active lifestyle is cancer Both physical and psychologicalbenefits are associated with physical activity for cancer survivors Indeed, multiplestudies during the past 20 years, coming from North America, Europe, Asia, andAustralia, have demonstrated that physical activity contribute to decrease the risk ofbreast cancer among female populations A 2008 review reported that physical activitywas associated with a 25 to 30% decrease in risk of developing breast cancer(Friedenreich & Cust, 2008), while a systematic review reported a 15 to 20%reduction in risk of breast cancer with higher physical activity, and a risk reduction ofabout 6% per hour of physical activity per week (Monninkhof et al., 2007) The resultsfrom the Nurses’ Health Study cohort and the Health, Eating, Activity and LifestyleStudy showed that women who are physically active after a breast cancer diagnosisare at lower risk of a recurrence and death caused by breast cancer (Holmes, Chen,Feskanich, & et al, 2005) In addition, physical activity play an important role inreducing fatigue, breast cancer-related lymphoedema, physical ability and health-related of life of breast cancer survivors (Headley, Ownby, & John, 2004; Johansson,Tibe, & Weibull, 2005; Mutrie, Campbell, & Whyte, 2007; Turner, Hayes, & Reul-

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Hirche, 2004)

In Vietnam, breast cancer is also the most common cancer among women acrossthe country In 2012, there were approximately 11,067 new cases of breast cancer andthe incidence rate was 23 per 100,000 women The number of deaths due to breastcancer was 4,671 cases and the mortality rate was 9.9 per 100,000 women (Ferlay etal., 2012) A 2012 report showed that Ha Noi and Ho Chi Minh are two cities in whichbreast cancer prevalence are highest Namely, the breast cancer prevalence in Ha Noi

is approximately 30 per 100,000 women and in Ho Chi Minh city is 20 per 100,000women (bachmaihospital, 2012) A review of Oncology Hospital, Ho Chi Minhshowed that breast cancer was accounted for 17.7% of all cases of cancer amongwomen in the period of 1998-1999; however, it increased up to 19.7% between 2003and 2004 (Nguyen, Le, Pham, & Dang, 2008)

An existing problem in breast cancer management in Vietnam is that a largeamount of breast cancer cases are lately diagnosed and the rate of late diagnosis is up

to 49.5% that predispose to difficulty in treatment regimens and reduced effectiveness

of breast cancer treatment Another concern comes from the fact that survivors afterbreast surgery do not receive adequate health cares, especially those related to physicalactivity, to prevent the recurrence of breast cancer Indeed, there are lack ofconsultations for survivors about how to and to what extent the exercises are doneduring three to seven days after surgery Consequently breast cancer survivors do notrecognize the importance of physical activity and they are reluctant to practicerecommended exercises As they are discharged, there are not any instructions on how

to perform physical activities at home provided and health facilities where survivorsare treated do not follow up their performance of physical activities as well

1.2 Significance of this research

The Oncology Hospital in Ho Chi Minh city is one of the largest hospitals in thecountry that serves as the main cancer center for treatment of patients from thesouthern of Vietnam It is estimated that 5,243 patients who have hospital admissionfor treatment of all kinds of cancer at the hospital each year; of these there are 15%women who have suffered and be treated breast cancer

After breast surgery, patients are participated in a physiotherapy program in

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which health care workers instruct patients to perform proper breathing and physicalactivities These activities are very important for patients to prevent atelectasis,pneumonia, scar contracture and improve the quality of life of patients as well For thefirst 3 to 7 days after surgery, patients should follow a designed program includingessential exercises such as deep breathing, moderate movement of affected arm, andcool-down exercises For six weeks after surgery, patients continue performing therecommended exercises at home and begin to practice jogging for 20 to 30 minuteseach day After four months, patients are asked to revisit the hospital for check-uphealth condition and receive more consultations on physical activities

The program has been established and applied for many years but theeffectiveness has not been evaluated yet In fact, during the first week after surgery,the performance of recommended exercises of patients could not be assessed because

of unknown reasons Moreover, not all patients were instructed and receivedconsultations on physical activity due to the fact that health care workers could nottake care of all patients There are not any surveys or studies conducted to investigatewhat patients have learnt from the program and what they thought about the exercises(unlike or frustrated towards the exercises) Finally patients do not report theirperformance of exercises at home so the evaluation of effectiveness of the program isimpossible To get the answers for all of these questions, a study therefore isnecessary

1.3 The aim of this research

The aim of the present study was to describe perceptions of patients on physicalactivity after breast surgery and prevalence of exercises performance The followingresearch objectives address the overall aim of this study

1 To describe the perceptions of physical activity among breast cancer survivors

2 To describe prevalence of exercise performance among breast cancer survivors

3 To identify the association between perceptions and other potential factors andperformance of exercises among breast cancer survivors

1.4 Chapter summary

Breast cancer is one of the most frequent cancers among women with the average

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number of death approximately 521,817 worldwide The incidence rates of breastcancer in different regions vary greatly with a higher trend in developed countries andlower trend in developing countries On the contrast survival rates of breast cancer inhigh-income nations have been increasing due to the fact that patients received bettercare, while theses figures appear to be lower in low- and middle-income nations.Physical activity is one of the most effective way to prevent the recurrence of breastcancer thank to its mental and physical effects Numerous studies have demonstratedthat physical activity can reduce the risk of acquiring breast cancer, incidence andmortality of breast cancer and improve quality of life of survivors.

The number of Vietnamese women who have breast cancer is estimatedapproximately 11,067 cases in 2012, yielding 23 cases per 100,000 women Of newcases, there are 4,671 women died from breast cancer, so the mortality rate is about9.9 cases per 100,000 women A problem exists in breast cancer management is thatwomen often have late diagnosis of breast cancer because they can not recognize signsand symptoms of the disease Moreover, lack of consultations about physical activityand insufficient physical practices after breast surgery make the risk of recurrence ofbreast cancer in these patients higher

Oncology Hospital at Ho Chi Minh city each year receives approximately of5,243 cases with all types of cancer including breast cancer (accounting for 15% oftotal cases) There is a physiotherapy program for survivors after breast surgeryestablished for years, but its effectiveness to date is still in question The physicalactivity of survivors after first 6 weeks of surgery and later could not be tracked;moreover, their perceptions of exercises that have a significant impact on exercisesperformance are not known Therefore, the present study focuses on evaluation ofperceptions of exercises among survivors after breast surgery, their prevalence ofexercises and the association between perceptions and exercise performance

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Chapter 2 Literature Review

2.1 Introduction

This chapter is a review of studies involving in the topic of the study Theepidemiology of breast cancer including statistics on incidence, mortality, survival rateand related factors those could affect the risk of developing breast cancer is described

at first Secondly, evidence of the impacts of physical activity toward breast cancerprevention will be the best explanation for the suggestion of performing exercises toprevent breast cancer A variety of impact mechanisms of physical activity that havebeen well documented are included in the third part of the chapter The fourth partintroduces recommendations of international guidelines toward physical activity forsurvivors after breast cancer Finally a wide range of studies are discussed to illustratethe prevalence of and related factors affecting to physical performance of survivorsglobally

2.2 Epidemiology of breast cancer

2.2.1 The burden of breast cancer worldwide

Breast cancer is the second most common cancer in the world and, by far, themost frequent cancer among women with an estimated 1.67 million new cancer casesdiagnosed in 2012 (25% of all cancers) (Ferlay et al., 2012) It is believed that breastcancer occurs more frequently in developed countries than in developing countrieswith incidence rates ranging from 27 per 100,000 in Middle Africa and Eastern Asia to

96 in Western Europe (Ferlay et al., 2012)

Breast cancer ranks as the fifth cause of death from cancer overall (522,000deaths) and while it is the most frequent cause of cancer death in women in lessdeveloped regions (324,000 deaths, 14.3% of total), it is now the second cause ofcancer death in more developed regions (198,000 deaths, 15.4%) after lung cancer(Ferlay et al., 2012) The range in mortality rates between world regions is less thanthat for incidence because of the more favourable survival of breast cancer in (high-incidence) developed regions, with rates ranging from 6 per 100,000 in Eastern Asia to

20 per 100,000 in Western Africa (Ferlay et al., 2012)

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2.2.2 Risks factors of breast cancer

Demographical factors

Age may be the strongest risk factors relating to breast cancer Women withadvancing age will have a higher risk of developing breast cancer compared toyounger women (Ferlay et al., 2012)

Socio-economical factors

Women who have higher social class have a higher risk of acquiring breastcancer (Kreiger, 1990) Studies have also showed that women living in developedcountries and have a high living standard have a higher risk of developing breastcancer The reason is that they have fewer children on average and shorter interval ofbreastfeeding (Collaborative Group on Hormonal Factors in Breast Cancer, 2002)

Reproductive factors

Women who have early age of menarche have higher risk of breast cancer(Tanner, 1973) However, late menopause also increases the risk of breast cancer withaverage of 3% increase risk when the age advances one year (Collaborative Group onHormonal Factors in Breast Cancer, 1997) Women who had children reduced the risk

of breast cancer approximately 30% when compared to women never having children.And women who have two issues will have reduced 15% risk compared to one issuewomen (Ewertz et al., 1990) Breastfeeding may be the protective factor to breastcancer but it is not certain However, the fact that breast never lactated is more prone

to cancer than a lactated breast (Thai & Nguyen, 2009; Tworoger, Eliassen, Sluss, &Hankinson, 2007)

Potentially modifiable risk factors include weight gain after age 18, beingoverweight or obese (for postmenopausal breast cancer), use of menopausal hormonetherapy (combined estrogen and progestin), physical inactivity, and alcoholconsumption Medical findings that predict higher risk include high breast tissuedensity (a mammographic measure of the amount of glandular tissue relative to fattytissue), high bone mineral density (women with low density are at increased risk forosteoporosis), and biopsy-confirmed hyperplasia (overgrowth of cells), especiallyatypical hyperplasia (overgrowth of abnormal cells) High-dose radiation to the chestfor cancer treatment also increases risk

Risk is also increased by a family history of breast cancer, particularly havingone or more first-degree relatives with breast cancer (though most women with breast

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cancer do not have a family history of the disease) Inherited mutations in breastcancer susceptibility genes account for approximately 5%-10% of all female breastcancers and an estimated 4%-40% of all male breast cancers, but are very rare in thegeneral population (much less than 1%) Most of these mutations are located inBRCA1 and BRCA2 genes, although mutations in other known genes have also beenidentified Individuals with a strong family history of breast and certain other cancers,such as ovarian and colon cancer, should consider counselling to determine if genetictesting is appropriate Prevention measures may be possible for individuals with breastcancer susceptibility mutations In BRCA1 and BRCA2 mutation carriers, studiessuggest that prophylactic removal of the ovaries and/or breasts decreases the risk ofbreast cancer considerably, though not all women who choose this surgery would havedeveloped breast cancer Women who consider prophylactic surgery should undergocounselling before reaching a decision

There is limited, but accumulating evidence that long-term, heavy smokingincreases the risk of breast cancer, particularly among women who began smoking at

an early age The International Agency for Research on Cancer has concluded thatthere is limited evidence that shift work, particularly at night, is also associated with

an increased risk of breast cancer

Modifiable factors that are associated with a lower risk of breast cancer includebreastfeeding (Lacey, 2009), moderate or vigorous physical activity, and maintaining ahealthy body weight (Danaei, 2005) Two medications including tamoxifen andraloxifene have been approved to reduce breast cancer risk in women at high risk.Raloxifene appears to have a lower risk of certain side effects, such as uterine cancerand blood clots; however, it is only approved for use in postmenopausal women

2.3 The impacts of physical activity toward breast cancer prevention

The study on association between physical activity and breast cancer might beginfrom two studies of Rose Frisch and Leslie Bernstein Rose Frish was the first scientistthat developed the physical activity–breast cancer hypothesis in the early 1980s In herstudy published in 1985, she noted that the prevalence of breast cancer in the non-athletes was about twice that of the college athletes (Odds ratio = 1.86 [95% CI: 1.00-3.47]) The next major advance in the physical activity–breast cancer hypothesis wasmade by Leslie Bernstein Her study in 1994 examining the role of lifelong exercise

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participation and breast cancer risk in young women (< 40 yrs) was a landmark studythat ignited research on the role of physical activity and breast cancer in particular, andphysical activity and cancer in general The results showed a strong inverserelationship between levels of lifetime exercise and estimated that women whoexercised for 3.8 hour/week or more had about a 60% reduction in risk for breastcancer compared to women who reported no exercise participation (Odds ratio = 0.42[95% CI: 0.27-0.64]) One year after the study of Leslie, Rohan et al (1995) examinedthe association between physical activity and breast cancer survival by conducting aprospective population-based study of 412 womenIn this study physical activity wasassessed before diagnosis and the association could not be found significantly.Consequently, later studies focused on studying the association after diagnosis

From the time of these innovative reports were published, many epidemiologicstudies and clinical trials have investigated the physical activity and breast cancerhypothesis and the accumulated evidence was sufficiently compelling that there isstrong evidence that physical activity may prevent breast cancer

2.3.1 Physical activity and risk of breast cancer

In 2,987 Nurses' Health Study (NHS) participants with 280 breast cancer deathsand 8 years median follow-up, women who exercised the equivalent of 3 to 5 hoursper week of walking had half the risk of dying of breast cancer (relative risk = 0.50,95% CI 0.38 to 0.84), with no evidence for increased benefit for greater exercise(Holmes et al., 2005) A systematic review reported a 15 to 20% reduction in risk ofbreast cancer with higher physical activity, and a risk reduction of about 6% per hour

of physical activity per week (Monninkhof et al., 2007) A 2008 review reported thatphysical activity was associated with a 25 to 30% decrease in risk across 62 studieswith 83% of the positive studies reporting a dose-response relationship (Friedenreich

& Cust, 2008)

2.3.2 Physical activity and mortality/survival/recurrence of breast cancer

There was also a reduced risk of breast cancer recurrence and total mortality, andthe benefit of physical activity was particularly apparent among women withhormone-responsive tumours (Holmes et al., 2005) The Collaborative Women's

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Longevity Study (CWLS) of 4,482 women with breast cancer followed for 6 yearswith 109 deaths reported a comparable decreased risk of breast cancer death and totaldeath (Holick et al., 2008) The Health, Eating, Activity and Lifestyle (HEAL) study

in 933 women reported a greater reduction in mortality for physical activity afterdiagnosis (67%) compared to physical activity measured before diagnosis (31%), and

a 45% decreased risk of death for women who increased their physical activity afterdiagnosis (Irwin, Smith, McTiernan, & et al, 2008) The Women’s Healthy Eating andLiving (WHEL) Study found that only when combined with higher fruit and vegetableintakes was exercise at 2 years post-diagnosis associated with favourable survival(Piercel et al., 2007) A small study of 603 breast cancer patients in Canada showed noassociation of breast cancer survival with exercise shortly after surgery (Borugian etal., 2004)

2.3.3 Physical activity and fatigue

Fatigue or cancer-related fatigue (CRF) usually begins in the second or thirdweek of treatment and may continue to increase for the duration of the therapy (Perun,

2004) This type of fatigue has consistently been reported by cancer patients as themost common and distressing symptom experienced during treatment, affecting 25%

to 93% of patients (Lawrence, Kupelnick, & Miller, 2004)

Exercise interventions implemented with cancer patients during active treatmenthave reported positive effects on subjective levels of fatigue Among women beingtreated for breast cancer, studies utilising home-based exercise programs have reporteddecreases in fatigue of between five and twenty percent post-intervention Incomparison, increased levels of fatigue (between 20 and 40%) have been reportedamong the usual care controls (Mock, Pickett, & Ropka, 2001; Schwartz, 2000) Arecent trial involving 108 women spanning the duration of their adjuvant therapy forbreast cancer, found women who adhered to a walking program reported significantlylower levels of fatigue (20% on average) compared to women who did not comply.The levels of fatigue for the non-compliers post-intervention more than doubled andwere in the moderate range compared to the mild or absent range for women whoadhered to the walking program (Mock, Frangakis, & Davidson, 2005) Decreases inlevels of subjective fatigue post-intervention have also been reported among mixed

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groups of cancer survivors in home-based (Courneya, Friedenreich, & Sela, 2003) andgroup-exercise programs (Adamsen, Quist, & Midtgaard, 2006) In addition, similarfindings have been found among advanced breast cancer patients for whom seatedexercise mitigated the effect of fatigue over the course of treatment (Headley et al.,

Cardiovascular problems and the presence of depressive symptoms wereidentified in one study as the two main correlates of long-term fatigue among breastcancer survivors (Bower, Ganz, & Desmond, 2006) Research has demonstrated thatboth depression (Brosse, Sheets, & Lett, 2002) and cardiovascular problems (Briffa,Maiorana, & Sheerin, 2006) can be positively influenced by regular physical activity.Physical activity interventions early after treatment therefore have the potential to notonly reduce fatigue, but to positively impact on these co-morbid conditions in thelonger term

2.3.4 Physical activity and breast cancer-related lymphoedema

Breast cancer-related lymphoedema (BCRL) has been described as one of themost distressing and unpleasant sequelae following surgery (Fialka-Moser, Crevenna,

& Korpan, 2003) A 2001 review reported the prevalence of BCRL (across treatmentsand time since treatments) to be approximately one in four women, with an overallprevalence of 26%, increasing over time (Erickson, Pearson, & Ganz, 2001)

As with fatigue, health professionals once cautioned breast cancer survivors toavoid participation in vigorous, upper-body exercise for fear of causing or aggravatinglymphoedema However, recent studies carried out with breast cancer survivors

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demonstrated that exercise did not exacerbate or lead to the development of BCRL Infact, two studies involving women with pre-existing BCRL reported a tendencytoward decreases in the volume of the affected arm (Johansson et al., 2005; Turner etal., 2004).

2.3.5 Physical activity and physical capability or fitness

A person’s fitness, also known as aerobic fitness, is measured objectively bymaximal oxygen uptake (USDHHS, 1996) This refers to the body’s ability to deliveroxygen to working muscles Most recently, two trials of eight- and 12-weeksupervised exercise interventions with breast cancer patients reported effect estimatesfor improvement in aerobic capacity of close to 1.0 and 0.7, respectively, at the end ofthe intervention compared to usual care controls (Daley, Crank, & Saxton, 2007;

Mutrie et al., 2007) Along with aerobic capacity, exercise interventions thatincorporated resistance training have shown improvements in other aspects of physicalfitness including strength (Adamsen et al., 2006; Kolden, Strauman, & Ward, 2002)and flexibility (Courneya, Friedenreich, et al., 2003; Kolden et al., 2002)

2.3.6 Physical activity and weigh gain

Weight gain has consistently been reported by women undergoing adjuvantchemotherapy A review looking at this issue reported that significant weight gainsoccurred in 50% to 96% of all patients with early-stage breast cancer who werereceiving adjuvant chemotherapy (Demark-Wahnefried, Rimer, & Winer, 1997).Weight gains between two and six kilograms appear to be most common (Lankester,Phillips, & Lawton, 2002), although much larger gains are not unusual (Demark-Wahnefried et al., 1997)

Regular physical activity has been the strongest predictor of weight stabilityamong breast cancer survivors (Demark-Wahnefried, Peterson, & Winer, 2001).Evidence from exercise interventions also supports this notion Participants assigned

to exercise either reduced or maintained their weight, while the weight of women incontrol groups increased (Schwartz, 2000) A similar positive outcome using the sum

of skin folds measure was observed among a group of mixed-cancer survivors at thecompletion of a 10-week therapy program The skin fold measure was significantly

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reduced among participants assigned to group therapy and exercise, while the skinfold measure significantly increased among participants assigned to group therapyalone (Courneya, Friedenreich, et al., 2003) Similar results have also been reportedamong survivors 14 months post-treatment (Courneya, Mackey, et al., 2003) Whilethe majority of these studies have utilised aerobic exercise, the incorporation ofstrength training directed towards the leg region may result in even greater benefits(Demark-Wahnefried et al., 2001).

2.3.7 Physical activity and health-related quality of life

Participation in exercise during active cancer treatment has been shown topositively impact on a patient’s overall health-related quality of life (HRQoL) andwell-being Two recent trials (both involving a 12-week exercise program with womenundergoing adjuvant therapy for breast cancer) described clinically important changes

in HRQoL between baseline and follow-up compared to usual care controls Womenwho were assigned to the exercise group reported a mean change in HRQoL ofapproximately 12 points at 12 weeks (Campbell, Mutrie, & White, 2005), while thesecond study reported an improvement of six points at six months follow-up (Mutrie

et al., 2007) A similar trend has been described for women with advanced-stagedisease A seated exercise intervention reportedly minimised the decline in globalHRQoL during chemotherapy for women diagnosed with stage IV breast cancercompared to controls (Headley et al., 2004)

2.4 The mechanism of physical activity affecting to breast cancer

Many studies have demonstrated that several physiological factors could affectthe risk of developing, recurrence and mortality of breast cancer These factors,directly or indirectly, are in turn affected by physical activities of patients

2.4.1 Physiological factors of breast cancer

Immune function

The immune system is thought to play a role in protecting against breast cancer

by recognizing and eliminating abnormal cells

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Mammographic density

Strong evidence exists that the characteristics of breast tissue as seen on amammogram, measured as mammographic density, provide information about breastcancer risk Women with high levels of mammographic density have a fourfold tosixfold greater risk of developing breast cancer than women with lower levels ofmammographic density; thus, mammographic density is a stronger predictor of breastcancer risk than most traditional risk factors Mammographic density reflectsproliferation of the breast epithelium and stroma, in response to growth factorsinduced by current and past circulating sex hormone levels Mammographic densitymay vary throughout lifetime, with the pattern reflecting the accumulated breastcancer risk at the time the mammogram was obtained Factors that changemammographic density may also change breast cancer risk

2002 ; McTiernan, 2006)

Androgens, such as testosterone, also may play a role in breast cancer Elevatedtestosterone levels were associated with increased risk for primary and secondarybreast cancer risk in both premenopausal and postmenopausal women (Calle,Rodriguez, & Walker-Thurmond, 2003; Irwin, McTiernan, & Baumgartner, 2005)

Body fat

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Body fat, or weight control, may also play an important role in mechanism ofdeveloping breast cancer (Irwin et al., 2005; Irwin, Yasui, & Ulrich, 2003; McTiernan,

2006) Women who gain weight after breast cancer diagnosis are at increased risk forbreast cancer recurrence and death as compared to women who maintain their weightafter diagnosis (Goodwin et al., 2002; Irwin et al., 2005; Neilson, Friedenreich, &Brockton, 2009) Analyses from a recent study showed that weight gain after diagnosis(~5 to 10 lbs) was related to approximately 50% higher rates of breast cancerrecurrence and death (Kroenke, Chen, & Rosner, 2005)

The influence of obesity on breast cancer risk varies by menopausal status:obesity has a protective effect against breast cancer in premenopausal women but isassociated with increased risk in postmenopausal women (Goodwin & Pritchard,

2010; Helzlsouer & Couzi, 1995) The biologic rationale for this difference in effect ofobesity on breast cancer risk is based on the source of endogenous estrogen before andafter menopause (McTiernan, 2006) Although menopausal status may modify theeffect of obesity on breast cancer risk, recent studies have shown a positive associationbetween weight gain during premenopausal or postmenopausal years and breast cancerrisk (Eliassen & Hankinson, 2008; McTiernan, 2006; McTiernan et al., 2003).Epidemiological studies have also shown that premenopausal and postmenopausalwomen who are overweight or obese when they are diagnosed with breast cancer aremore likely to experience a recurrence or die of breast cancer than women who are of

a normal weight (McTiernan, 2006) Furthermore, some, but not all, studies suggestthat women who gain weight after breast cancer diagnosis, regardless of menopausalstatus, are at increased risk for breast cancer recurrence and death as compared withwomen who maintain their weight after diagnosis (McTiernan, 2006) This isespecially worrisome given the fact that most women who are treated for breast cancergain a significant amount of weight in the year after breast cancer diagnosis, andreturn to pre-diagnosis weight rarely occurs (Irwin et al., 2005)

Insulin and Insulinlike Growth Factors (IGF)

Insulin, insulin-like growth factor-1 (IGF-I) and IGF-binding proteins (IGFBP)are believed to be important mechanisms associated with the development of breastcancer In a study of women with early-stage breast cancer, higher insulin levels were

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associated with a two and three times higher risk of recurrence or breast cancer death,respectively (Goodwin et al., 2002) Another study also confirmed that IGF-I have amajor role in promoting breast cancer (McTiernan, 2006) The explanation is thatinsulin and IGF-1 can enhance tumor development by stimulating cells to multiply andinhibiting cells from dying, or undergoing programmed cell death (i.e., apoptosis)(Gray, Stenfeldt-Mathiasen, & De Meyts, 2003; Kaaks & Lukanova, 2001; Yu &Rohan, 2000).

IGFBPs are important determinants of the bioavailability of IGF-1, and IGFBP-3

is an important carrier of IGF-1 in circulation IGFBP-3 also may either stimulate orsuppress cells from multiplying by restricting the availability and biological activity ofIGF-I (Gray et al., 2003; Yu & Rohan, 2000) Although the data are not consistent,high levels of IGF-I and low levels of IGFBP-3 have been associated with anincreased risk of breast cancer and adverse prognostic factors after a diagnosis ofbreast cancer (Calle et al., 2003; Hankinson et al., 1998; Morimoto, White, & Chen,

Biomarkers of low-grade chronic inflammation, such as C-reactive protein(CRP), serum amyloid A (SAA), tumor necrosis factor-α (TNF-α), and interleukin(IL)-6, have been linked with increased cancer risk (Il’yasova, Colbert, & Harris,

2005) Although there is limited epidemiologic literature on inflammation and breastcancer risk (Neilson et al., 2009), these biomarkers of inflammation may affect breastcancer through their effects on apoptosis, cell proliferation, angiogenesis, and

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metastasis (DeNardo & Coussens, 2007) Chronic inflammation has also beenassociated with higher rates of recurrence and death for several cancers includingbreast cancer (Ardizzoia & Brivio, 1992; Monninkhof et al., 2007) Breast cancerpatients have been shown to have elevated concentrations of CRP prior to surgery, andCRP is higher in women with more advanced stage of disease (McMillan, Sattar,Angerson, Johnstone, & McArdle, 2001)

Oxidative Stress/DNA repair

Reactive oxygen species (i.e., free radicals) can play a significant role in breastcancer via their ability to produce DNA damage as well as damage to other cellularcomponents which interact with DNA (McTiernan, 2006)

2.4.2 Evidence for impacts of physical activity to risk factors of breast cancer

Physical activityand immune function.

A growing literature of small exercise intervention studies shows that physicalactivity improves immune function, both functionally and numerically (McTiernan,

2006) Physical activity appears to enhance proliferation of lymphocytes, increases thenumber of natural killer cells and increases lymphokine-activated killer cells activity.Therefore, physical activity has a protective affect to breast cancer

Physical activity and mammographic density.

Physical activity may influence mammographic density by favourably changingcertain hormones associated with mammographic density and breast cancer risk Bothmammographic dense area and percent density have been found to be inversely related

to physical activity in obese postmenopausal women (McTiernan, 2006; Pierce,Faerber, & Wright, 2002)

Physical activity and sex hormones.

Changes in sex hormones are perhaps the most consistently cited potentialmechanism for the association between physical activity and breast cancer Girls whoparticipate in athletics tend to have a later age of menarche and a delay in establishing

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normal ovarian cyclicity Later age of menarche and slowed establishment of cyclingwould decrease the total steroid hormone exposure to the breast (McTiernan, 2006) Inadult premenopausal women, exercise has been associated with decreased levels ofcirculating estrogen and progesterone, shortened luteal phase, increased frequency ofanovulation, and an increased incidence of oligomenorrhea and amenorrhea Inpostmenopausal women, physical activity has been found to be associated withdecreased serum estrogens and androgens (McTiernan, 2006; McTiernan et al., 2004).Increased physical activity also has been associated with increased sex hormone-binding globulin resulting in lower amounts of free active sex hormones in circulation(EHBCCG, 2002 ; McTiernan et al., 2004)

The primary mechanism of physical activity influencing sex hormones inpostmenopausal women is via decreased body fat, a substrate for estrogen, andtestosterone production, which results in less tissue capable of aromatization of theadrenal androgens to estrogens Only one randomized controlled exercise trial hasbeen published examining the effect of exercise on sex hormone concentrations(McTiernan et al., 2004) The authors examined the influence of a 12-month exerciseprogram in postmenopausal women on these hormonal factors and found that exercisedecreased serum estrogens and androgens, and increased SHBG resulting in loweramounts of free, active estrogens and androgens Women who lost more body fat withexercise were noted to have larger changes

Physical activity and body fat.

Few trials have examined the effect of exercise on outcomes of body composition

in breast cancer survivors McTiernan (2006) demonstrated that obese individualsgenerally exhibit a lower level of habitual physical activity than the non-obese, andphysically active individuals may be less likely to become obese.(McTiernan, 2006) In

a recent publication, moderate-intensity aerobic exercise, such as brisk walking,performed for approximately 120 min/wk, was associated with modest, yet favourable,changes in body fat in postmenopausal breast cancer survivors (Irwin, Alvarez-Reeves, & Cadmus, 2009)

Physical activity and insulin and IGF

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Few trials that have assessed the effect of exercise on IGFs have had variableresults Irwin and colleagues (2009) showed that moderate-intensity aerobic exercise,such as brisk walking, performed on average for 120 min/wk over six months wasassociated with a 25% decrease in insulin and 7% decrease in IGF-1 among exercisers,and a 5% increase in insulin and 2% increase in IGF-1 among controls (21) Giventhat high insulin levels promote the synthesis and activity of IGF-I via increases ininsulin-mediated changes in IGFBP-3 concentrations, decreases in insulin would bepredicted to favourably influence IGF levels.

Physical activity and adipocytokines.

Few trials have examined the effects of physical activity on adiponectin in breastcancer survivors Recently, Irwin and colleagues (2008) examined the effect of sixmonths of moderate-intensity aerobic exercise versus usual care on leptin andadiponectin levels in 75 breast cancer survivors Baseline correlations between leptin,adiponectin, and measures of adiposity were strong and consistent with availableliterature; however the intervention did not result in statistically significant differences

in levels of leptin or adiponectin between exercisers and usual care participants

There is evidence that physical activity might reduce chronic inflammation alone,

or by reducing body weight or composition (McTiernan, 2008), given thatinflammatory factors have been shown to correlate with body fat (Vona-Davis, 2007).However, little is currently known about the effect of physical activity on CRP, IL-6,and TNF-α in breast cancer survivors

Physical activity and DNA repair

Acute exercise may promote free radical production, whereas chronic exerciseimproves free radical defences by up-regulating both the activities of key free radicalscavenger enzymes and levels of antioxidants To date, there are few studies that haveexamined reactive oxygen species-related damage or relevant antioxidant enzymes inthe context of exercise in a cancer model

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Figure 1 Hypothesized relationship between physical activity and primary andsecondary breast cancer risk (Source: (Irwin, 2006))

2.5 Recommendations of physical activity after surgery for breast cancer survivors

2.5.1 The first 1 to 7 days after surgery

These gentle exercises should be done the first week after surgery or while thedrain is still in place It’s normal to feel your skin and tissue pull and stretch a bit withthese exercises, but be careful not to make any sudden movements until the incisionhas healed and the drain has been removed Repeat these exercises 3 to 4 times a day

Deep breathing Deep breathing is an important part of your recovery and helps

expand your chest wall It helps with relaxation and can remind you to fill your lungscompletely

1 Try lying on your back or sitting and then take a slow, deep breath through yournose Breathe in as much air as you can while trying to expand your chest andstomach like a balloon

2 Do not tense your shoulders or neck

3 Relax and breathe out slowly and completely

4 Repeat 4 or 5 times

Pump it up This exercise helps reduce swelling after surgery by using your muscles as

a pump to improve the circulation in your affected arm (on the same side as yoursurgery)

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1 Try lying on your unaffected side with your affected arm straight out, above thelevel of your heart (use pillows if you need to) Or sit in a chair with good backsupport with your arm supported by pillows.

2 Slowly open and close your hand Repeat 15 to 25 times

3 Then slowly bend and straighten your elbow Repeat 15 to 25 times

Shoulder shrugs and circles This exercise can be done sitting or standing

1 Lift both shoulders up towards your ears Keep your chin tucked in slightly Holdfor 5 to 10 seconds, and then slowly drop them down and relax Repeat 5 to 10times

2 Gently rotate both shoulders forward and up, and then slowly back and down,making a circle Keep your chin tucked in slightly Switch and repeat in theopposite direction

3 Repeat 5 to 10 times in each direction

Arm lifts This exercise can be done sitting or standing

1 Clasp your hands together in front of your chest Point your elbows out

2 Slowly lift your arms upwards until you feel a gentle stretch

3 Hold for 1 to 2 seconds, and then slowly return to the start position

4 Repeat 5 to 10 times

Shoulder blade squeeze This exercise helps improve movement in your shoulder and

your posture

1 Sit in a chair facing straight ahead without resting your back on the chair, or stand

up Your arms should be at your side with your elbows straight and your palmsfacing your sides

2 Open your chest, gently squeeze your shoulder blades together and down androtate your thumbs so your palms face forward

3 Hold for 5 to 10 seconds and practice your deep breathing while holding thisposture Relax and return to the start position

4 Repeat 5 to 10 times

2.5.2 The first 6 weeks after surgery

Once your drain has been removed, it’s important to try to get back the full use ofyour shoulder Begin with these easy exercises and then move on to the moreadvanced exercises once you feel stronger By the end of this stage, you should havefull movement of your affected arm and shoulder You shouldn’t feel worse after the

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exercises During this stage of healing, do not lift anything heavier than about 5 kg (10lbs) –this amount may depend on the surgery you had.

As well as these following exercises, keep doing the shoulder blade squeezeexercises that you were doing right after surgery

Wand exercise (2 positions) This exercise helps improve the forward movement of

your shoulder You will need a “wand” to do this exercise – try a broom handle, stick

or a cane You may feel a gentle pull but not any pain or pinching during theseexercises If you do, stop the movement before the point of pain or pinching

Winging it This exercise helps improve movement in the front of your chest and

shoulder It may take several weeks of regular exercise before your elbows get close tothe floor If you feel pain or pinching in your shoulder, place a small pillow behindyour head, above (not under) your affected shoulder

1 Lie on your back with your knees bent Touch your fingertips to your ears withyour elbows pointed to the ceiling (If you can’t comfortably put your hands atyour ears, place your fingers on your forehead, palms facing each other.)

2 Move your elbows apart and down to the bed (or floor)

3 Hold for 1 to 2 seconds

4 Repeat 5 to 10 times

Wall climbing This exercise helps increase movement in your shoulder Try to reach a

little higher on the wall each day This exercise can be done in 2 directions – facingthe wall or your affected side to the wall

Facing the wall

1 Stand facing the wall, about 5 cm (2 inches) away Place both your hands on thewall at shoulder level

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2 Use your fingers to climb up or slide as high as you can go until you feel a stretch.

3 Return to start position

4 Repeat 5 to 10 times

Side wall stretch

1 Stand with your affected side to the wall, about 2 feet from the wall so you cantouch the wall with your fingertips

2 Walk your fingers up the wall as you do in facing the wall Do not rotate yourbody towards the wall Keep your torso facing forward even if it means you can’t

go up as high

3 Lower and repeat 5 to 10 times

Snow angels This exercise can be done lying down on the floor or on a bed.

1 Lie on your back and extend your arms out at your sides

2 Move them up over your head, eventually touching your fingers, and then backdown to your thighs (as if you’re making an angel in the snow)

3 Repeat 3 to 5 times

Once you’re getting better movement in your shoulder, try these more advancedstretches

Side bends This exercise helps improve movement on both sides of your body

1 Sit in a chair and clasp your hands together in your lap

2 Slowly lift your arms over your head Bend your elbows slightly

3 When your arms are above your head, bend at your waist and move your body tothe right Hold 1 to 2 seconds Use your right hand to gently pull your left arm alittle further to the right Keep yourself firmly planted on the chair Take a deepbreath in and out

4 Return to the centre and then bend to the left, using your left hand to pull yourright arm further

5 Repeat 5 to 10 times on each side

Continue these exercises until both arms are equally strong and can move easily.This may take 2 to 3 months When you can reach across the top of your head andtouch your opposite ear without feeling a stretch in your underarm, then you haveachieved full movement of your arm

It’s safe to do light housework during the first 6 weeks after surgery Do only shortperiods at a time and rest in between You can start heavier activities after 6 weeks

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Always let pain be your guide – a little discomfort is okay but more pain could meanyou’re doing too much.

2.5.3 From about 6 weeks after surgery

As you feel stronger, you can gradually start doing strengthening and generalconditioning exercises For some women, this means getting back to their old exerciseroutine, but for others it may mean trying out some new activities

Talk to your doctor or another member of your healthcare team about starting aspecific strengthening program or aerobic exercise, and ask if there are any specialprecautions you should take

If you have pain, your shoulder is tight or your hand or arm begins to swell, talk toyour doctor or another member of your healthcare team

But it is important to build up slowly If you don’t exercise for several days, reducethe amount of weight slightly and build up again

General conditioning

Regular aerobic exercise, which is any exercise that gets your heart and lungsworking hard, improves your general physical condition

It can help with your recovery and has many benefits It can:

1 Help improve your cardiovascular fitness – how well your heart, lungs and bloodvessels bring oxygen to your muscles – so that you can do physical work forlonger periods of time

2 Help you maintain a healthy body weight

3 Help you feel better, which may reduce stress and anxiety

4 Help you as you face the challenges of life after cancer

Brisk walking, swimming, running, cycling, cross-country skiing and dancing areall examples of aerobic exercise

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2.6 Prevalence and factors affecting prevalence of physical activity among breast cancer survivors

2.6.1 Prevalence of physical activity among breast cancer survivors

A growing number of studies have looked at the prevalence of physical activityamong women with breast cancer, reporting estimates between 9% (Pinto, Trunzo, &Reiss, 2002) and 74% (Nelson, 1991) This large variation can be explained by theresearchers’ different definitions of physical activity, the timing of measurement, thetype of instrument used and the overall study design Combined, these factors make itdifficult to compare findings across studies, as well as to establish physical activityparticipation rates among women with breast cancer

The pattern of physical activity among cancer survivors has been well described

in the literature Evidence suggests that physical activity decreases during the activetreatment stage and then begins to increase again post-treatment (Courneya &Friedenreich, 1997a, 1997b) In a cross-sectional survey (pre-diagnosis activity levelswere measured retrospectively), Courneya (1997a) described a significant 43%decrease in the number of women reporting physical activity during active treatmentand conversely a 47% increase post-treatment Even with their more relaxed definition

of “active” (being at least one weekly session for 15 minutes), a definite pattern ofchange in activity was seen

Irwin and colleagues (2003) described a significant decrease in the total activity

of breast cancer survivors by 11% (120 minutes) per week from the year pre-diagnosis

to within 12 months post-diagnosis The largest decrease of 51% was seen forvigorous activity, while moderate activity decreased by 19% The type of treatmentreceived had a substantial impact on a woman’s level of activity Women treated withsurgery and chemotherapy, or surgery, chemotherapy, and radiation, had the largestsignificant decreases in activity as opposed to surgery alone or in conjunction withradiation

A population-based study of breast cancer survivors suggested that by three yearspost-diagnosis, sports and recreational activity had returned to pre-diagnosis levelswhich averaged between 2.5 and 3.5 hours per week However, this was only seen in

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approximately 50% of the women (Irwin, McTiernan, & Bernstein, 2004) In contrast,

a longitudinal study of women with early-stage breast cancer reported that afteradjuvant therapy, activity levels quickly returned to those reported pre-diagnosis(Andrykowski, Beacham, & Jacobsen, 2007)

A longitudinal study tracking the natural progression of physical activity fromeight to 20 months post-diagnosis found no significant increase in either vigorous- ormoderate-intensity activity over time (Pinto et al., 2002) An average of 33 minutesper week of vigorous activity at baseline increased by just four minutes 12 monthslater For moderate-intensity activity, the baseline average of 65 minutes increased by

38 minutes While these changes were not statistically significant and the averagesremained well below guidelines, the trend (particularly for moderate activity) wastowards an increase in activity over time More importantly, the numbers of womenparticipating in each activity increased between baseline and 20 months post-diagnosis The number of women who reported participating in any vigorous activityincreased from 13% at baseline to 29% 12 months later The number of womenreporting any moderate exercise increased from 42% to 54% This trend would benormal as more and more women complete their treatment and begin to get back intotheir usual routine

2.6.2 Factors affecting prevalence of physical activity

Along with prevalence rates, the examination of factors that influence physicalactivity participation by breast cancer survivors is of interest Data in this area wouldallow researchers to identify subgroups of women who would benefit from increasingtheir exercise behaviour Studies have indicated that advancing age (Pinto, Maruyama,

& Engebretson, 1998; Pinto et al., 2002), higher BMI (Pinto & Trunzo, 2004), and adiagnosis of stage II disease (Pinto et al., 1998) negatively impact a woman’slikelihood of physical activity participation after diagnosis Social support, includingliving with a partner (Pinto et al., 2002), having an exercise role model or exercisepartner (Rogers et al., 2005), having higher levels of confidant support (e.g chances totalk about problems) and affective support (love and affection, caring) (Pinto et al.,

1998), and a higher income (Rogers et al., 2005) were each positively associated withparticipation

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Physical activity has been shown to be a beneficial behavior for the prevention ofbreast cancer due to its diverse impacts on physical and mental health of women withbreast cancer A large body of clinical trials and observational studies has indicatedthat physical activity could reduce the risk of developing, mortality and recurrence ofbreast cancer but increase the survival rate in patients Besides, other benefits ofphysical activity include reducing fatigue or depression after treatment in survivors,preventing breast-cancer related lymphoedema, recovering fitness and physical ability

of patients, and finally improve their quality of life The biological mechanismsthrough which physical activity may produce protections include a favorable influence

on sex hormones, insulin-related pathways, the prevention of weight gain and obesity,and potential effects on adipokine levels and inflammatory pathways

Recommendations for physical activity could be divided into phases after breastcancer For the first one to seven days after surgery, survivors could perform essentialexercises such as deep breathing, pump it up, shoulder shrugs and circles etc toprevent complications in affected side During first 6 weeks, continuation ofperforming new exercises such as wall exercise, winging it, wall climbing etc andstarting light housework with short time is recommended More than 6 weeks aftersurgery is the proper time for performing strengthening and general conditionexercises

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The prevalence of exercises after breast surgery among survivors has been welldocumented with a higher rate of performance in developed countries than that indeveloping countries Several factors that have great impacts on exercise performance

of patients include advancing age, higher BMI and stage II of the disease On thecontrast, some protective factors include having an exercise role model or exercisepartner, high level of confidant support, affective support and higher income

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Chapter 3 Research Methodology

3.1 Introduction

This chapter constitutes of five parts including research design, researchframework, sampling issues, data management and data analysis and ethic issues.Since the main goal of the study is to investigate prevalence of exercise, a cross-sectional study is necessary A study framework with application of Health BeliefModel is thought to be reasonable for exploring perceptions of exercise among thesubjects of the study Sample size, sample technique, sample criteria and samplingprocedure are important components of methodology that must be described in anystudies In data management and data analysis section, methods of controlling errorsand chances during data collection along with statistical techniques utilized duringdata analysis are depicted clearly and comprehensively Finally, ethic issues areconsidered so that the study does not violate ethical regulations both of MeihoUniversity and Oncology Hospital

3.2 Research design

The study was a cross-sectional study carried out in Oncology Hospital, Ho ChiMinh city from January to February 2014

3.3 Research framework and hypotheses

In the field of behavioral science, it is essential to apply a model of healthbehavior to identify potential factors affecting studying behavior The present studyaims to identify prevalence of exercises of breast cancer survivors and theirperceptions of exercises, so employing a model of health behavior in the study isnecessary The Health Belief Model, one of the most popular models of healthbehavior, will be applied in this study

The initial model of Health Belief Model includes four main components:perceptions of possibility of acquiring disease, perceptions of severity of disease,perceptions of benefits of health behavior, perceptions of barriers toward performinghealth behavior However, by the time the model was modified with another

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Perceptions of suggestion about performing exercises after breast cancer surgery

Perceptions of social supports

Performing excercises after breast cancer surgery

Perceptions of threaten of breast cancer after surgery

Perceptions of possibility of recurrence of breast cancer after surgery

Perceptions of severity of breast cancer

The desire of expected outcomes

Perceptions of the benefits of exercises

Perceptions of barriers of performing excercises

Sociodemographic characteristic

component called perceptions of suggestion for actions All of these components will

be used in the study in accordance with perceptions of social supports, general healthvariables, breast cancer treatment variables, and socio environmental factors Therelationships among these components are described in Figure 2

Figure 2 Research framework

3.4 Sampling issues

3.4.1 Sample size

All patients who visit the Oncology Hospital for re-examination after breastcancer surgery from January 2014 to February 2014 will be the target for enrolling inthe study

3.4.2 Sampling technique

Because the study has a complete sample, the sampling technique should be fullsampling method All patients who met the inclusion and exclusion criteria wererecruited to the study

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3.4.3 Sampling criteria

Inclusion criteria

Women who had received breast cancer surgery in Oncology Hospital precedingthe time of study Women who are voluntary to participate in the study by signing ininformed consent

of the study and the benefits of participants if involving in the study If subjectsvoluntarily agree to participate in the study, an informed consent was obtained Thecollectors explained how to complete the questionnaire and answer any question fromthe participants

3.5 Data management and data analysis strategy

3.5.1 The questionnaire

A questionnaire that is structured based on previous studies (Le, 2013; Nijhof, terHoeven, & de Jong, 2008) and practical settings at Oncology Hospital will be used forthe study The questionnaire includes following sections:

• Section A (5 items): Sociodemographic characteristics including age, education,family income, marital status, occupation;

• Section B (8 items): General health information including height (m), weight (kg),BMI (kg/m2 ),menopause status, family history of breast cancer, smoking status,alcohol consumption, comorbidities, family history of breast cancer, cigarettesmoking, alcohol consumption);

• Section C (7 items): Breast cancer treatment (type of surgery, chemotherapy,radiotherapy, immunotherapy, tomoxifen, interval from surgery to studyenrolment, recurrence of breast cancer);

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• Section D (53 items): Perceptions of exercises after breast cancer includingperceptions of possibility of recurrence of breast cancer, perceptions of severity ofbreast cancer, perceptions of the benefits of performing exercises, perceptions ofbarriers of performing exercises, perceptions of suggestion of performingexercises, perceptions of social support.

• Section E (21 items): Prevalence of performing exercises

3.5.2 Evaluation of reliability and validity of the questionnaire

To check the content validity of the questionnaire, we conducted a pilot study with

17 breast cancer patients (did not included in the study) interviewed by a primaryquestionnaire on December 2013 (one month prior to the study time) The primaryquestionnaire also included five sections like the official questionnaire, but the number

of items related to perceptions were much more (61 items instead of 53 items) Theresults of the pilot study showed that 8 items related to perceptions of exercises in theprimary questionnaire were not well recognized by patients As a result, we removed 8items and revised the primary questionnaire to form the official questionnaire Theofficial questionnaire then was delivered to Director Board of the Oncology (fiveexperts on oncology field) to check the consistency of the official questionnaire All ofexperts agreed with the official questionnaire and approved the researcher to conductthe study in the hospital

To examine the reliability of the questionnaire, thirty breast cancer who visited theOncology on December, 2013 was interviewed with the official questionnaire Thereliability of questionnaire was measured by Cronbach’s α The average correlation ofitems related to perception of suggestion and social supports were not high (< 0.8),while other perception had high internal consistency

Table 1 The results of reliability analysis

Perceptions of possibility of recurrence of breast cancer

after surgery

Items D1-D7 0.82

Perceptions of severity of breast cancer Items D8-D17 0.81

Perceptions of the benefits of exercises Items D18-D23 0.84

Perceptions of barriers of performing excercises Items D24-D43 0.83

Perceptions of suggestion about performing exercises

after breast cancer surgery

Items D45-D49 0.77

3.5.3 Data collection technique

Perception assessment

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Each item involving in perception assessment will be evaluated by five pointsLikert scale from strongly disagree (1 point), disagree (2 point), undecided (3 point),agree (4 point) to strongly agree (5 point) The total score for perception of eachcomponent in the model will be the average of scores of items in that component Forexamples, the perceptions of social support constitute of 5 items and the score of eachitem is 5, so the total score of perception of social support will be 5 The more higherthe average of score had, the more perceptive patients experienced

Exercise assessment

All participants would be asked about their exercises that they performed atdifferent times after surgery including the first 7 days after surgery, first 6 weeks aftersurgery, and the interval from 6 weeks after surgery to the day they complete thequestionnaire Besides asked about type of exercises, they also will be asked about thefrequency of these exercises

3.5.4 Data analysis strategy

Data entry and data analysis was performed by using SPSS 16.0 Qualitativevariables would be summarized by frequency, proportion and tested by chi-square test.Quantitative variables would be described by mean, standard deviation and t test, ifnecessary P < 0.05 was considered statistically significant

3.6 Ethic issues

This study was approved by Expert Committee of Oncology Hospital Onlypatients who were willing to participant in and signed in the informed consent wereincluded in the study Before interviewing, patients were always informed about thepurposes of the study After the interview if patients had the needs of consulting ofexercises practicing, investigators always instructed and guided patients In addition,all data related to patients would be coded and only used for studying purposes