Exercise and Breast Cancer

I vividly remember the day years ago when a very close friend found out that she had breast cancer.  It seemed completely unbelievable – she was only 36 and still nursing her seven-month-old baby. The experience of watching someone very close to me go through surgery, chemotherapy, and radiation sparked an interest in working with women undergoing breast cancer treatment.  I became fascinated with the possibility of regular physical activity reducing, or altogether mitigating, the side-effects of cancer treatment. It is fairly well-established that exercise can help prevent breast cancer.  In 2009 a paper published in Medicine & Science in Sports & Exercise, the journal of the American College of Sports Medicine, reported that age-adjusted breast cancer mortality rates per 10,000 women were 4.4, 3.2, and 1.8 for low, moderate, and high cardio-respiratory fitness levels, respectively.  This was after controlling for possible confounding variables including body mass index, smoking, drinking, chronic health conditions, abnormal exercise ECG responses, family history of breast cancer, oral contraceptive use, and estrogen use.  The study authors used 14,811 women who were enrolled in longitudinal study on general aerobic exercise. Recently researchers have pinpointed that high levels of insulin and insulin-like growth factor (IGF-1), often seen in sedentary individuals, can increase the risk of breast cancer recurrence and death.  Women with breast cancer who engage in regular aerobic exercise can reduce the presence of these hormones in their bodies, thus reducing the possibility of the cancer returning.  Along the same lines, a 2005 study of 3000 breast cancer patients found that just one hour of walking per week significantly increased the likelihood of making a full recovery. What is not as widely recognized is that regular exercise can mitigate the symptoms of cancer treatment.  This includes:

  • Increased functional capacity
  • Increased mobility and range of motion (ROM) post-mastectomy
  • Decreased body fat
  • Increased lean muscle mass
  • Reduced loss of bone mineral density
  • Decreased nausea and fatigue
  • Improved natural defence mechanisms
  • Improved sense of control
  • Improved mood
  • Improved self-esteem

A systematic meta-analysis published in the Journal of the Canadian Medical Association in 1996 that analyzed data from 14 studies found that the benefits of exercise were positive even when statistical significance was not achieved.  The outcomes that were measured were quality of life, cardiovascular fitness, physical functioning, fatigue, body composition, and adverse treatment effects. Please - encourage any women in your life who have breast cancer to exercise!  Do this if the woman has

  • Been recently diagnosed
  • Is going to have surgery
  • Is post surgery
  • Is undergoing chemotherapy or radiation
  • Has completed her treatment

Regular aerobic, strength and flexibility training will make each of these stages easier both psychologically and physically! References American Cancer Society (2005).  Exercise Can Improve Breast Cancer Survival.  American Cancer Society: Cancer.org. Irwin et al (2009).  Randomized Controlled Trial of Aerobic Exercise on Insulin and Insulin-like Growth Factors in Breast Cancer Survivors: The Yale Exercise and Survivorship Study.  Cancer Epidemiology, Biomarkers and Prevention. McNeely et al. (2006).  Effects of exercise on breast cancer patients and survivors: a systematic review and meta-analysis.  Journal of the Canadian Medical Association. Peel, JB (2009).  A prospective study of cardiorespiratory fitness and breast cancer mortality.  Medicine & Science in Sports & Exercise.