It isn't known for sure whether having a vasectomy (an operation to cut or tie off the two tubes that carry sperm from the testicles) can increase a man's risk of developing prostate cancer many years later. Most doctors believe either that vasectomy has no effect on the risk of prostate cancer or that, if it does increase the risk, the effect of this is quite small.

Studies that have compared men who have had vasectomies with men who haven't, to see if one group was more likely to get prostate cancer, have given different results. Most studies found that having a vasectomy made no difference to a man's risk. But, a few suggested an increased risk for men who had had a vasectomy.

Most of the studies that found an increased risk for men after a vasectomy looked at only small numbers of men. Small studies are more likely to give results that could be due to chance, so are less reliable than large studies. Because of this, doctors think the results of these studies could be due to chance rather than show a real effect of vasectomy on prostate cancer risk.

Many specialists in prostate cancer agree it is unlikely that vasectomy increases the risk of developing prostate cancer. And, although a link can't be ruled out altogether, if there is an increase in risk this is probably small.

References:

• Cancer and cardiovascular disease after vasectomy: an epidemiological database study. Goldacre MJ et al 2005 Fertility and sterility 84(5) 1438-43.
• Vasectomy and the risk of prostate cancer: A meta-analysis examining status, age at vasectomy, and time since vasectomy. Dennis L K et al 2002 Prostate Cancer Prostatic Diseases. 5(3):193-203.