Lifetime total physical activity and prostate cancer risk: a population-based case–control study in Sweden

The etiologic role of physical activity in prostate cancer development is unclear. We assessed the association between lifetime total physical activity and prostate cancer risk in a Swedish population-based case-control study comprising 1,449 incident prostate cancer cases and 1,118 unaffected population controls. Information regarding physical activity was obtained via a self-administered questionnaire assessing occupational, household, and recreational activity separately at various ages throughout an individual's lifetime. Clinical data (TNM-classification, Gleason sum and PSA) was obtained from linkage to the National Prostate Cancer Registry. Overall, we observed no association between lifetime total physical activity and prostate cancer risk (odds ratio [OR] = 1.04, 95% confidence interval [CI] = 0.77-1.41 for > or =49.7 vs. <41.9 metabolic equivalent-hours per day). There was a significantly increased risk of prostate cancer in the most active men compared with the least active men in household (OR = 1.44, 95% CI = 1.08-1.92) and recreational physical activity (OR = 1.56, 95% CI = 1.16-2.10). Comparing the most active with the least active men, total physical activity was not associated with either localized disease (OR = 0.95, 95% CI = 0.67-1.34) or advanced disease (OR = 1.19, 95% CI = 0.83-1.71). These findings do not support the hypothesis that physical activity uniformly protects against prostate cancer development.