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TWO STUDIES LINK VASECTOMY TO PROSTATE CANCER.

Some data have suggested a link between vasectomy and prostate cancer. These researchers used two major, ongoing cohort studies to assess this proposed association.

As part of the Health Professionals Follow-up Study, they prospectively followed 10,055 men who had had vasectomies and 37,800 who had not. The men were enrolled in 1986; during the next five years, 300 new cases of prostate cancer were diagnosed. Men with a history of vasectomy had a 66 percent higher age-adjusted risk for prostate cancer. The increased risk was even greater -- 85 percent -- in the subset of men who had undergone vasectomy at least 22 years earlier. Similar findings emerged from a retrospective study of husbands of women from the Nurses' Health Study. The researchers identified 14,607 women who had reported vasectomy as the couple's form of contraception in 1976 to 1978 and 14,607 age-matched controls whose husbands had not had vasectomies. This cohort had 96 prostate cancers diagnosed from 1976 through 1989; compared to controls, the risk was 56 percent higher in men with a vasectomy and 89 percent higher in men who had their vasectomy at least 20 years earlier.

These data indicate a moderate increase in risk for prostate cancer after vasectomy. Both studies appear to control for possible detection bias (i.e., improved diagnosis of prostate cancer among vasectomized men). However, it may be that the risk is not from vasectomy itself but from some unknown factor associated with both vasectomy and prostate cancer. This possibility can only be excluded by a randomized trial -- which is unlikely ever to be performed.

— THL

Published in Journal Watch General Medicine March 2, 1993

Citation(s):

Giovannucci E et al. A retrospective cohort study of vasectomy and prostate cancer in US men. JAMA 1993 Feb 17 269 878-882.

• Medline abstract (Free)

Giovannucci E et al. A prospective cohort study of vasectomy and prostate cancer in US men. JAMA 1993 Feb 17 269 873-877.

• Medline abstract (Free)