When people talk about the benefits of exercise for cancer survivors, they often talk about quality of life issues: greater feeling of control, easing side effects of treatment, improved self image. But there are plenty of data showing benefits for overall outcomes - reducing the risk of relapse and death - for several cancers.
The best evidence, so far, for the benefits of exercise comes from studies of breast cancer patients.
So, what do we know?
In 2005, results were released from the Nurses' Study and published in the
Journal of the American Medical Association which found that regular, moderate exercise (3-5 hours of walking or equivalent of moderate exercise) reduced the risk of breast cancer recurrence by about 50%. The study followed nearly 3,000 nurses who were diagnosed with stage I, II, or III breast cancer between 1984 and 1998.
In another study, Dr. Melinda Irwin, PhD, MPH, associate professor of epidemiology and public health at the Yale School of Medicine, and colleagues found that moderate physical activity reduced the risk for death by all causes by 67% in women with breast cancer who remained active 2 years after diagnosis. The Health, Eating, Activity and Lifestyle (HEAL) study was published in 2008 in the
Journal of Clinical Oncology.
A
study by Dr. Christine Friendenreich and colleagues, of the Alberta Health Services-Alberta Cancer Board in Calgary, Canada, followed 1,231 women for 8.3 years. The women who exercised at least 4 hours per week over their lifetime had a 44% lower risk of breast cancer death. In addition, similar levels of exercise reduced the risk for women already diagnosed with breast cancer of recurrence, progression, or new primary breast cancer by 34%.
There have been other studies with slightly different variables (looking at only post or pre-menopausal women, or different exercise intensities) that have had somewhat different results. However, all show improvement in breast cancer outcomes with exercise. Depending on the exact measurements, exercise reduces the risk of breast cancer death by anywhere from 40 - 55%, which is as much as standard treatment.
I often tell people that I love to exercise, but even if I hated it, with numbers like that I'm out there walking!
We also know that exercise reduces the risk of developing breast cancer in the first place. That's why it's important for all of us to encourage our friends, daughters, nieces, and sisters to be active.
Of course, there are variables we can't control. I was very active and healthy, and I developed breast cancer at an early age. I will never know why. But there is much we
can do to improve our chances.
So go out for a walk, ride a bike, go dancing. And better yet, take along someone you care about - improve her chances, too.
Julie