1. Kennedy, Maureen Shawn MA, RN

Article Content

The Nurses Health Study, an ongoing, long-term study out of Boston, has yielded a wealth of information over the years. The latest report gives some encouraging news about the relationship between breast cancer recurrence and exercise: just three to five hours per week of walking at an average pace may reduce the risk of death from breast cancer by 50%. From the 121,700 female RNs enrolled in this prospective observational cohort study, 2,987 women who were diagnosed with stages I, II, or III breast cancer between 1984 and 1998 were surveyed about their level of physical activity at least two years after diagnosis. The women were then followed "until death or 2002, whichever came first". There were 370 recurrences of breast cancer, 280 breast cancer deaths, and 463 total deaths (12.4%, 9.4%, and 15.5% of the sample, respectively).


Different forms and intensity of exercise were converted to metabolic equivalent (MET) hours of physical activity: one hour of walking at an average pace was equivalent to three MET hours of physical activity; walking was the most popular physical activity among the study participants.

FIGURE. No caption a... - Click to enlarge in new windowFIGURE. No caption available.

After adjusting for multiple biologic and social variables, the researchers found that walking even one hour per week was associated with a reduction in the risk of breast cancer recurrence, death from breast cancer, and death from all causes. Compared with walking less than an hour a week, the greatest benefit was seen among women whose physical activity was the equivalent of walking three to five hours per week at an average pace, among whom the adjusted relative risk of breast cancer recurrence was 0.57; of breast cancer deaths, 0.50; of death from all causes, 0.59. More vigorous or lengthy exercise did not produce additional benefit.


The absolute unadjusted risk reduction gained from physical activity was significant: the 10-year survival rate was only 86% among women who walked less than an hour a week but was 89% among women who walked one to three hours per week and 92% among women who walked three or more hours per week. The authors suggest that by following recommendation of at least 30 minutes of moderate exercise at least five days a week, breast cancer survivors can improve their chances of survival. -Fran Mennick, BSN, RN


Holmes MD, et al. JAMA 2005;293(20):2479-86.