Researchers are calling for prostate cancer survivors to incorporate physical activity into their daily routine.
The recommendation was issued by a team from the Harvard School of Public Health, Brigham and Women's Hospitals, and Harvard Medical School in Boston, Massachusetts, and the University of California, San Francisco, who found that prostate cancer survivors who exercise regularly can decrease their risk of prostate cancer-specific and overall mortality.
The study also showed that men who did more vigorous physical activity for longer durations had the lowest risk of dying from the disease. Vigorous exercise was defined as more than 3 hours of weekly exercise.
Stacey A. Kenfield, ScD, with the Harvard School of Public Health, and associates analyzed data in 2705 men who had been diagnosed with nonmetastatic prostate cancer between 1990 and 2008 in the 51,529-patient, prospective Health Professionals Follow-Up Study. Prostate cancer is the most frequently diagnosed cancer in men in the United States, and more than 2 million men in this country are prostate cancer survivors, Kenfield said.
While studies have shown that breast and colon cancer survivors who perform regular physical activity have significantly lower overall mortality and cancer-specific mortality than survivors who do not exercise regularly, this association has not been evaluated in prostate cancer survivors, she noted.
Prior research by her group had shown that high levels of vigorous physical activity were significantly associated with a decreased risk of advanced prostate cancer in men aged 65 years and older.
In the present analysis, trial participants completed questionnaires every 2 years that focused on their leisure-time activities. Specifically, they were asked to report the average amount of time they spent each week during the prior year performing physical activities (eg, walking, jogging, running, riding a bicycle, swimming, tennis, etc), as well as heavy outdoor work and weight training. The men were also asked to cite the frequency, duration, and intensity of physical activity.
Of the 548 deaths that occurred during follow-up, 112 (20%) were due to prostate cancer. The median length of follow-up from the first post-diagnosis physical activity assessment was 9.7 years for survivors and 7.8 years for patients who died.
Both vigorous activity and nonvigorous activity were associated with significantly lower overall mortality. Men who walked 90 minutes or more per week at a normal to very brisk pace had a 46% lower risk of all-cause mortality (HR, 0.54) compared to men who walked for a shorter length of time at a slower pace.
Men who did 3 or more hours per week of vigorous activity had a 61% lower risk of prostate cancerspecific death than men who did less than 1 hour of vigorous activity per week (HR, 0.39; P
In a news release, Kenfield points out that benefits were achieved--at very attainable levels--of activity, thereby suggesting that prostate cancer patients should do some form of physical activity for their overall health. Even as little as 15 minutes a day may be useful, she said. Vigorous activity for at least 3 hours per week confers additional benefit by potentially preventing both prostate cancer deaths and deaths from all causes.
Further research, however, is needed to determine whether physical activity can thwart prostate cancer progression, and also to identify optimal exercise regimens, she added.
_________________________________________________________Kenfield SA, Stampfer MJ, Giovannucci E, Chan JM. Physical activity and survival after prostate cancer diagnosis in the Health Professionals Follow-Up Study. J Clin Oncol. 2011 Jan 4. [Epub ahead of print] doi:10.1200/JCO.2010.31.5226.Published in Oncology & Biotech News. February 2011.