Vigorous physical activity may slow prostate cancer

Vigorous physical activity does not seem to affect the risk of developing prostate cancer, but it may slow the progression of disease in older men, new research suggests.

Previous studies have yielded conflicting results regarding the effects of exercise on prostate cancer risk, lead author Dr. Edward L. Giovannucci, from Harvard School of Public Health, and colleagues note. “However, many of the studies were not designed to examine physical activity in detail.”To investigate the association further, Dr. Giovannucci’s team analyzed data from nearly 50,000 men who participated in the US Health Professionals Follow-up Study. Over 14 years of follow-up, the subjects were asked detailed questions about exercise activity every other year. Overall, 2892 new cases of prostate cancer were diagnosed, including 482 involving advanced disease. As noted, the overall risk of prostate cancer was not influenced by physical activity, the investigators report in the Archives of Internal Medicine for May 9th. However, among men 65 years of age or older, those engaging in at least 3 hours of vigorous physical activity per week were 67% less likely to be diagnosed with advanced disease than were inactive men. For fatal disease, the risk reduction was even more pronounced, at 74%.This association in older men did not seem to stem from screening bias or from undiagnosed prostate cancer causing a reduction in physical activity. By contrast, no association between vigorous physical activity and slower disease progression was seen in younger men, the authors point out. Among men with prostate cancer, the risk of a Gleason grade 7 or higher malignancy fell as physical activity rose, the findings show.”Although the mechanisms still need to be understood, these findings suggest that vigorous activity could slow the progression of prostate cancer and might be recommended to reduce mortality from prostate cancer, particularly given the many other documented benefits of exercise,” the authors conclude. (Source: Arch Intern Med 2005;165:1005-1010: Reuters Health: Oncolink: May 2005.)