A medical riddle that arose more than a decade ago is now closer to resolution. Three studies in the early 1990s suggested that men who had undergone vasectomy seemed more apt to get prostate cancer than were men who hadn’t had the procedure. Other studies found no connection, but uncertainty has lingered.
Researchers in New Zealand report in the June 19 Journal of the American Medical Association that men with prostate cancer are no more likely to have had a vasectomy than healthy men are.
Between 1996 and 1998, the researchers scoured data from a national cancer registry and located 923 men between the ages of 40 and 74 who had had prostate cancer at some point. The scientists matched these men with 1,224 men of similar age who hadn’t had prostate cancer.
Follow-up interviews revealed that roughly one-fourth of the men in both groups had had a vasectomy, says study coauthor Brian Cox, a medical epidemiologist at the University of Otago School of Medicine in Dunedin. Also, roughly equal portions of men in each group had had their vasectomies at least 25 years before the study, indicating that the operation imparts no long-term risk of cancer.
“The findings of our study provide very strong evidence that no increased risk of prostate cancer from vasectomy exists,” says Cox.
“I think a lot of people breathed a sigh of relief when they saw this,” says Steven C. Kaufman, a physician and epidemiologist at the National Institute of Child Health and Human Development in Bethesda, Md., which partially funded the study.