Vasectomy and Increased Risk of Prostate Cancer

To the Editor. —The higher rates of prostate cancer reported in men who have had vasectomies¹ do not prove that vasectomies cause prostate cancer. I believe that the behavior of men who have had vasectomies is responsible for their higher rates of prostate cancer. Prostate cancer is associated with human papillomavirus² and a high-fat diet.³ Men who have vasectomies are more likely to be sexually active. Since they do not need to worry about impregnating women, they may be more promiscuous; they are far less likely to use condoms, and thus, they increase their risk of acquiring venereal warts. It would be interesting to see if they are also more likely to eat a high-fat diet.