Exercise and prostate cancer risk in a cohort of veterans undergoing prostate needle biopsy.

PURPOSE: Epidemiological and molecular evidence suggest potential associations between exercise and prostate cancer risk reduction. We further characterized this relationship by examining exercise and cancer risk among men undergoing prostate needle biopsy.
MATERIALS AND METHODS: A total of 190 men who underwent prostate biopsy at the Durham Veterans Affairs Medical Center completed a questionnaire on current exercise behavior. Participants were asked average frequency of mild, moderate and strenuous intensity exercise in a typical week, as well as average duration as assessed by the Godin Leisure Time Exercise Questionnaire. Total current exercise was calculated in terms of metabolic equivalent task hours per week. Primary outcome measures were prostate biopsy result and Gleason sum.
RESULTS: After adjusting for age, race, body mass index, prostate specific antigen, digital rectal examination, family history, previous prostate biopsy and comorbidity score, men who reported 9 or more metabolic equivalent task hours per week of exercise were significantly less likely to have cancer on biopsy (OR 0.35, CI 0.17-0.75, p = 0.007). Furthermore, among men with malignant biopsy results, reporting moderate exercise (3 to 8.9 metabolic equivalent task hours weekly) was associated with a lower risk of high grade disease (Gleason 7 or greater, OR 0.14, CI 0.02-0.94, p = 0.04).
CONCLUSIONS: To our knowledge these results provide the first evidence of an association between exercise and prostate cancer risk as well as grade at diagnosis in men scheduled to undergo prostate biopsy. Specifically moderate exercise was associated with a lower risk of prostate cancer and in men with cancer, lower grade disease. Further investigation using an objective measure of exercise in a larger sample size is required to confirm these findings.