Vasectomy and risk of prostate cancer

In 1993, the Journal of the American Medical Association revealed a connection between vasectomy and an increased risk of Prostate cancer. Reported studies of 48,000 and 29,000 men who had vasectomies showed 66 percent and 56 percent higher rates of Prostate cancer, respectively. The risk increased with age and the number of years since the vasectomy was performed.
However, in March of the same year, the National Institute of Child Health and Human Development held a conference cosponsored by the National Cancer Institute and others to review the available data and information on the link between Prostate cancer and vasectomies. It was determined that an association between the two was very weak at best, and even if having a vasectomy increased one's risk, the risk was relatively small.
In 1997, the NCI held a conference with the Prostate cancer Progressive Review Group (a committee of scientists, medical personnel, and others). Their final report, published in 1998 stated that evidence that vasectomies help to develop Prostate cancer was weak at best.