Abstract A117: Physical activity and survival after prostate cancer diagnosis

Abstract

Abstract Context: Higher levels of physical activity have been linked with a lower risk of advanced prostate cancer (PCa), but no studies have examined whether activity post-diagnosis is beneficial for PCa survivors. Objective: To assess the relationship between physical activity, and duration and pace of walking, with total and PCa-specific mortality. Design, Setting, and Participants: Prospective study of 2,686 men in the Health Professionals Follow-up Study diagnosed with PCa, and with follow-up from 1986 through 2008. Physical activity was assessed repeatedly both before and after diagnosis. To generate the total activity score, we summed activity-specific metabolic equivalent (MET)-hours per week. To reduce the potential influence of disease on activity level, we excluded from the analysis men with diagnosed metastases at diagnosis, and we only utilized activity information from four to six years before death. We used multivariable Cox proportional hazard models adjusted for risk factors for PCa mortality. We calculated hazard ratios for total mortality and PCa-specific mortality. Results: Of the men who were alive for at least 4 years after their post-diagnosis physical activity assessments, we documented 554 deaths, with 22% due to prostate cancer. Men who were physically active, especially those engaging in 3 or more MET-hours of total activity, had a 35% lower risk of death from any cause (hazard ratio, 0.65 [95% CI, 0.52, 0.82]) and a modest non-significant reduction in risk of prostate cancer death (hazard ratio, 0.88 [95% CI, 0.52, 1.49]), after adjustment for other risk factors for PCa mortality and pre-diagnosis physical activity. While no benefit from walking was observed for PCa mortality, men who walked 4 or more hours per week versus those who walked less than 20 minutes per week had a 23% lower risk of all-cause mortality (95% CI, 0.61, 0.97; p-trend=0.01). In addition, compared to men who walked less than 90 minutes at an easy walking pace, those who walked 90 or more minutes at a normal to very brisk pace had a 51% lower risk of all-cause mortality (95% CI, 0.37, 0.64). More vigorous activity, and longer duration of activity, was associated with significant further reductions in risk for all-cause mortality. More vigorous activity was associated with a borderline-significant reduction in risk for PCa mortality. Conclusions: In a cohort of men with PCa, physical activity was associated with a lower risk of overall mortality. Regular vigorous activity may reduce mortality from prostate cancer. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A117.