**7. Barriers to physical activity in cancer survivor and in their physicians**

Cancer survivors are not only at increased risk for progressive disease but also a host of comorbid conditions (other cancers, cardiovascular disease, obesity, diabetes and osteoporosis), functional decline and premature death (Demark-Wahnefried et al., 2006a). The impact of exercise is beyond the effects on cancer survival rate as exercise is also associated with other benefits for cancer survivors: exercise is consistently associated with improved quality of life, and also is effective in improving physical functioning (oxygen capacity, cardiorespiratory fitness, other fitness or strength measures, flexibility and global health), anthropometric measures (weight status, body fat, waist circumference) and healthrelated biomarkers (blood pressure, heart rate, circulating hormonal levels) among cancer survivors (Demark-Wahnefried et al., 2006a).

Therefore initiating and maintaining an exercise regimen long term should be generalized in the growing population of cancer survivors. In other words, cancer survivors should be encouraged to initiate and maintain physical activity.

However, adoption and maintenance of physical activity is a difficult challenge for healthy adults and is likely to be even more difficult after a cancer diagnosis. Concerning physical activity, cancer survivors are faced to two types of barriers:



This suggests that interventions to increase physical activity in patients should be multifactorial and multidirectional, i.e. directed towards patients and their physicians.

#### **7.1 Cancer survivor barriers to adoption and maintenance of physical activity**

As a result of the cancer diagnosis, surgery and adjuvant treatments some cancer survivors experience fatigue, depression anxiety, reduced overall quality of life (Irwin, Smith, McTiernan, Ballard-Barbash, Cronin, Gilliland, Baumgartner, Baumgartner, & Bernstein 2008). All these comorbid conditions favor sedentarity.

Patients should be informed and educated on the role of physical activity, not only to aid in the prevention of cancer but also to improve survival rates following diagnosis.

Thus, oncologists and physicians should discuss with their patients the benefits of physical activity after a diagnosis of cancer, reassure them that exercise is safe and associated with improved overall survival and quality of life, and to refer them to a certified cancer exercise trainer who will prescribe an exercise program that is tailored to them. The oncologist and

In summary, exercise can alter biological processes that contribute to both anti-initiation and anti-progression events in the carcinogenesis process. However, more detailed studies are needed to examine each of the potential mechanisms contributing to an exercise-induced decrease in carcinogenesis in order to determine the minimum dose, duration and frequency of exercise needed to yield significant cancer-preventive effects, and whether exercise can be used prescriptively to reverse the sedentarity-induced and obesity-induced physiological

Moreover, the mechanisms of the beneficial effects of regular physical activity on survival after cancer treatment, and most importantly on the quality of life (decreased post-treatment fatigue, improved symptoms secondary to treatment) have yet to be determined (not to mention the need to know when to begin physical activity in relation to treatment, and at

**7. Barriers to physical activity in cancer survivor and in their physicians** 

Cancer survivors are not only at increased risk for progressive disease but also a host of comorbid conditions (other cancers, cardiovascular disease, obesity, diabetes and osteoporosis), functional decline and premature death (Demark-Wahnefried et al., 2006a). The impact of exercise is beyond the effects on cancer survival rate as exercise is also associated with other benefits for cancer survivors: exercise is consistently associated with improved quality of life, and also is effective in improving physical functioning (oxygen capacity, cardiorespiratory fitness, other fitness or strength measures, flexibility and global health), anthropometric measures (weight status, body fat, waist circumference) and healthrelated biomarkers (blood pressure, heart rate, circulating hormonal levels) among cancer

Therefore initiating and maintaining an exercise regimen long term should be generalized in the growing population of cancer survivors. In other words, cancer survivors should be

However, adoption and maintenance of physical activity is a difficult challenge for healthy adults and is likely to be even more difficult after a cancer diagnosis. Concerning physical

This suggests that interventions to increase physical activity in patients should be multifactorial and multidirectional, i.e. directed towards patients and their physicians.

As a result of the cancer diagnosis, surgery and adjuvant treatments some cancer survivors experience fatigue, depression anxiety, reduced overall quality of life (Irwin, Smith, McTiernan, Ballard-Barbash, Cronin, Gilliland, Baumgartner, Baumgartner, & Bernstein

Patients should be informed and educated on the role of physical activity, not only to aid in

Thus, oncologists and physicians should discuss with their patients the benefits of physical activity after a diagnosis of cancer, reassure them that exercise is safe and associated with improved overall survival and quality of life, and to refer them to a certified cancer exercise trainer who will prescribe an exercise program that is tailored to them. The oncologist and

changes that increase cancer risk (Rogers et al., 2008).

what dose: duration and intensity).

survivors (Demark-Wahnefried et al., 2006a).

encouraged to initiate and maintain physical activity.

activity, cancer survivors are faced to two types of barriers:

2008). All these comorbid conditions favor sedentarity.



**7.1 Cancer survivor barriers to adoption and maintenance of physical activity** 

the prevention of cancer but also to improve survival rates following diagnosis.

certified exercise trainer should also consider any preexisting conditions and adverse effects of treatment (Irwin et al., 2008).

It is necessary to take into account the state of fatigue of the patients before prescribing a program of physical activity. In all cases, the prescription must be individualized and implemented very gradually.

#### **7.2 Barriers of physicians to prescribe physical activity in cancer survivors: What physicians should know, understand and explain to their patients**

There is a reluctance of oncologists and of physicians to prescribe physical activity. Many elements prevent them from providing exercise advice: lack of sufficient knowledge of the benefits of being physically active after a cancer diagnosis, fear of side-effects of exercise (cardiovascular risks, lymphedema). Finally most physicians do not have the training or resources to develop individualized exercise prescription for cancer survivors.

#### **7.2.1 Physician should know, understand and explain the wide spectrum of health benefits of physical activity**

In addition to the risk of recurrence of the cancer, cancer survivors are also at risk of chronic fatigue, loss of muscle mass, weight gain. It should be noticed that the average weight gain after breast cancer treatment is 3-5 kg, and that epidemiological studies have shown that weight gain after a cancer diagnosis is associated with an increased risk for recurrence and death compared with maintaining normal weight after diagnosis (Kroenke et al., 2005). Cancer survivors also have the same risks as the general population to develop cardiovascular diseases or metabolic diseases, or even they present an increased risk of developing these as obesity and a sedentary lifestyle are highly prevalent in cancer survivors. Specifically there is evidence that cancer survivors die of noncancer causes at a higher rate than persons in the general population (deaths being primarily from cardiovascular diseases and diabetes) (Carver et al., 2007).

As detailed in paragraph 3.4, physical activity can reduce risk of other chronic diseases (cardiovascular diseases and diabetes) on one hand, and on the other hand, physical activity may help subjects with cancer avoid dying from their cancer.

#### **7.2.2 Physician should know, understand and explain that physical activity in cancer survivor is safe and well-tolerated**

The published work provides sufficient evidence to suggest that exercise is a safe and welltolerated supportive intervention that oncologists can recommend to their patients after the completion of primary treatment.

In one of the largest studies to date, Courneya and colleagues examined the effects of aerobic exercise alone, resistance exercise alone, or usual care, on fitness, muscular strength, body composition, and quality of life in 242 breast cancer survivors initiating chemotherapy (Courneya et al., 2007). There were significant favorable effects of both aerobic and resistance exercise on multiple outcomes including self esteem, fitness, and body composition, as well as increased chemotherapy completion rates compared with usual care. Furthermore, no significant adverse events were reported; lymphedema did not increase or was not exacerbated by aerobic or resistance exercise. Recently, other clinical trials of women with breast cancer have shown no increased risk for or exacerbation of lymphedema from either aerobic and/or resistance exercise (Ahmed et al., 2006).

Physical Activity and Cancer: It is Never Too Late to Get Moving! 121

Oncologist and primary care physicians should not lose sight of the fact that a substantial body of research shows the benefit of a healthy diet and regular exercise for reducing risk for many of the comorbid conditions (ie, other cancers, cardiovascular disease, diabetes, and osteoporosis) and side-effects (ie, fatigue and depression) for which cancer survivors are especially prone. Thus, oncology care providers can assist their patients by endorsing existing health guidelines for their patients and for themselves and encouraging their patients to take active roles in pursuing general preventive health strategies (Jones &

There is a large body of evidence that physical activity has an important role in prevention and management of cancer: physical activity reduces risk of breast and colon cancer, during and after cancer treatment physical activity ameliorate symptom experience, ameliorate treatment side effects, improve quality of life and reduce mortality and morbidity. As such, regular physical activity should be encouraged in all populations (general population, subjects at high risk of cancer, survivors of cancer… and in physicians) throughout all life. Now, the question is not: "why should I prescribe physical activity in my patients?" but "How initiating and maintaining physical activity in patients?". Initiating exercise is important; however, maintaining an exercise regimen long term is a significant challenge. Behavioural interventions are complex and involve multidisciplinary approach (patients, physicians, scientists, government, urbanists…). Whatever, it's time to get moving and it is

Abramson, S., Stein, J., Schaufele, M., Frates, E.& Rogan S.: Personal exercise habits and

Ahmed, R.L., Thomas, W., Yee, D., & Schmitz, K.H. (2006) Randomized controlled trial of

Barbaric, M., Brooks, E., Moore, L., & Cheifetz, O. Effects of physical activity on cancer

Carver, J.R., Shapiro, C.L., Ng, A., Jacobs, L., Schwartz, C., Virgo, K.S., Hagerty, K.L.,

Chan, A.T. & Giovannucci, E.L. Primary prevention of colorectal cancer. *Gastroenterology,*

Chatard, J.C., Duclos, M., Rossi, D.& Toutain, J. Androgens, skeletal muscle and muscle

Courneya, K.S. Exercise in cancer survivors: an overview of research. *Med.Sci.Sports Exerc*.

Courneya, K.S., Segal, R.J., Mackey, J.R., Gelmon, K., Reid, R.D., Friedenreich, C.M., Ladha,

A.B., Proulx, C., Vallance, J.K., Lane, K., Yasui, Y., & McKenzie, D.C. (2007) Effects

survival: a systematic review. *Physiother.Can*., 62 (2010), 25-34. Calle, E.E. & Thun, M.J. Obesity and cancer. *Oncogene*: 23 (2004), 6365-6378.

pulmonary late effects. *J Clin.Oncol.* 25 (2007): 3991-4008.

exercise. *Progress in Urology***,** 14 (2004): 703-717.

counseling practices of primary care physicians: a national survey. *Clin J Sport Med*

weight training and lymphedema in breast cancer survivors. *J Clin.Oncol.*, 24

Somerfield, M.R., & Vaughn, D.J. American Society of Clinical Oncology clinical evidence review on the ongoing care of adult cancer survivors: cardiac and

Demark-Wahnefried, 2006).

never too late to get moving!

10 (2000):40-48.

(2006), 2765-2772.

138 (2010): 2029-2043.

35 (2003): 1846-1852.

**9. References** 

**8. Conclusion** 

Courneya and colleagues also completed a similar trial of aerobic exercise vs usual care in breast cancer survivors who had completed adjuvant treatment, and observed similar favorable effects of exercise on fitness and overall quality of life (Courneya et al., 2003). Overall, these, and other, studies have demonstrated that exercise is safe in cancer survivors and produces beneficial effects on quality of life and cancer-related symptoms with no adverse side effects.

A long-term concern in breast-cancer survivors starting an exercise program is lymphoedema. The few studies that have assessed this issue clearly showed that upper body exercise does not induce or exacerbate lymphoedema, and on the contrary, it would seem that a suitable AP allow to limit this risk.

#### **7.2.3 Physician should know and understand the influence of their beliefs on physical activity on the beliefs and physical activity of their patients**

General practitioners (GP) are cited as the primary source of information influencing healthy lifestyle decisions, but few studies have evaluated whether GPs' perceived barriers towards physical activity affect physical activity uptake in their patients. In type 2 diabetes patients, Duclos et al. (2011) have assessed the associations between GPs' perceived barriers to prescribing physical activity and type 2 diabetes patients' perceived barriers to adopting physical activity. Their findings showed that GPs' physical activity and GPs' perceived barriers, are associated with type 2 diabetes patients' physical activity. An effect of GPs barriers on patients' ones towards physical activity was depicted since the higher the GP's barriers score, the higher the type 2 diabetes patient's barriers score. Examining the nature of perceived barriers to physical activity in both type 2 diabetic patients (regarding physical activity practice) and their GPs (regarding physical activity prescription), common barriers emerged with a high score: "A low fitness level", "The fear of being tired", "Their actual physical health status, excluding diabetes", "The fear of suffering a heart attack". These common barriers are inconsistent with evidence-based medicine (Haskell et al., 2007). These results are consistent with the hypothesis that the beliefs of GPs might influence the beliefs of their type 2 diabetes patients. Finally, GPs' physical activity was positively correlated with their patients' physical activity.

It has been shown that endorsement of physical activity is more credible coming from a professional who practices physical activity (Abramson et al., 2000). GPs should practise physical activity themselves, not only for their own benefit, but also as a stimulus for physical activity of their patients (Duclos et al., 2011).

It remain to determine if this proves to be the case in cancer survivors. However this suggests that identifying and working on GPs' barriers but also promoting physical activity in GPs may improve the uptake of physical activity in their patients.

#### **7.2.4 Recommendations for physicians**

As in other clinical and non-clinical populations, cancer survivors should obtain clearance from their physician or oncologist program. This clearance is especially important in cancer survivors who are at high risk for late-occurring toxic effects secondary to treatment that can increase their risk of cardiovascular disease. Thus, appropriate screening procedures for cardiac and cardiovascular disease are recommended before an exercise program is started.

The prerequisite is that patients have obtained the prior agreement of their cancer specialist and that patients should be screened for osteoporosis, bone metastasis, cardiac toxicities, and lymphedema.

Oncologist and primary care physicians should not lose sight of the fact that a substantial body of research shows the benefit of a healthy diet and regular exercise for reducing risk for many of the comorbid conditions (ie, other cancers, cardiovascular disease, diabetes, and osteoporosis) and side-effects (ie, fatigue and depression) for which cancer survivors are especially prone. Thus, oncology care providers can assist their patients by endorsing existing health guidelines for their patients and for themselves and encouraging their patients to take active roles in pursuing general preventive health strategies (Jones & Demark-Wahnefried, 2006).
