Vasectomy is not associated with either an increased risk of prostate cancer or of dying of such cancer, according to the results of a large prospective study published in the Journal of Clinical Oncology.
The study, “Vasectomy and Prostate Cancer Incidence and Mortality in a Large US Cohort,” was conducted by Eric Jacobs, PhD, and his colleagues from the American Cancer Society, based in Atlanta.
Vasectomy is a common surgical procedure for men wanting to be sterilized, a permanent and highly effective method of birth control. A number of studies have addressed whether this procedure increases the risk of prostate cancer, but results were often mixed. Among the six published studies, three reported a positive association between vasectomy and prostate cancer risk, while the other three did not.
Then, in 2014, the largest study to date linked this procedure to a modestly higher risk of prostate cancer (10%), especially high-grade and lethal prostate cancer, kindling the debate.
“Although a previous study suggested an association, our results show no connection between vasectomies and overall risk for prostate cancer, or of dying of prostate cancer, and should provide some reassurance to men considering vasectomy,” said Jacobs, in a news release. “Men concerned about developing a fatal prostate cancer should focus on maintaining a healthy weight and, if they smoke, quitting smoking. Both obesity and smoking having consistently been linked with high risk for fatal prostate cancer, as well as with risk for many other diseases.”
To understand whether vasectomy contributed to prostate cancer development or mortality, the researchers examined data from two groups: 363,726 men from the Cancer Prevention Study II (CPS-II), of whom 7,451 died from prostate cancer during the follow-up period of the study, and a subgroup from this study, with 66,542 men who entered the CPS-II Nutrition study, and of whom 9,133 were diagnosed with prostate cancer during follow-up.
A total of 42,015 men from the first study and 10,589 men from the second study had undergone a vasectomy. The researchers noticed that these men had more education and were less likely to smoke or be obese.
Results showed that vasectomy was not associated with increased risk of prostate cancer development or mortality, regardless of the length of time that passed since the surgery. In fact, vasectomy was even associated with a lower risk for prostate cancer mortality in the CPS-II Nutrition cohort.
The main limitation of this study is the fact that the report on the vasectomy status of the patients was made by their wives, which can introduce some bias in the conclusions of the study. But the team said it is confident that their results support that vasectomy is unlikely to be a determinant factor in the development of prostate cancer.