Clinical Question: Is ejaculation frequency related to an increased risk of prostate cancer?
Study Design: Cohort (prospective)
Synopsis: Infrequent ejaculation may increase the risk of prostate cancer because of retained carcinogenic secretions in the prostate gland. To examine this relationship, the authors analyzed data from the Health Professionals Follow-up Study, a large prospective study involving 29,342 men 46 to 81 years of age. Participants provided information on their history of ejaculation frequency from 1992 through January 31, 2000. Questionnaires, which were mailed to participants at baseline and again every two years, asked for an estimate of the average number of ejaculations per month during the ages of 20 to 29 years, 40 to 49 years, and during the past year. Study investigators, who were blinded to the questionnaire data, evaluated medical information to identify cases of prostate cancer.
A total of 1,449 cases of prostate cancer were identified, including 147 cases of advanced disease. No association of an increased risk of prostate cancer was found with any category of ejaculation frequency. However, the relative risk (RR) of prostate cancer was decreased in men who reported high ejaculation frequency (i.e., 21 or more episodes per month compared with four to seven episodes per month) at ages 20 to 29 years (RR = 0.89; 95 percent confidence interval [CI], 0.73 to 1.10), at ages 40 to 49 years (RR = 0.68; 95 percent CI, 0.53 to 0.86), and in the previous year (RR = 0.49; 95 percent CI, 0.27 to 0.88). For each increment of three ejaculations per week across a lifetime, the risk of prostate cancer was reduced by 15 percent. No statistically significant association existed between ejaculation frequency and the risk of advanced prostate cancer.
Bottom Line: Ejaculation frequency is not associated with an increased risk of prostate cancer. High ejaculation frequency (i.e., 21 or more episodes per month) may reduce the risk of prostate cancer. (Level of Evidence: 2b)