Men who had had a permanent vasectomy have an increased risk by 10% of developingprostate cancer, according to a recent study that was conducted for 24 years on nearly50,000 men. The correlation relates particularly aggressive and deadly forms prostate cancer.
Vasectomy is a surgical procedurethat involves clamping, cutting, or sealing the vas deferens from each testicle that carries sperm to the seminal stream (ejaculate) in order to prevent fertilization from occurring. It is a common contraception (birth control) in Anglo-Saxon countries. According to a recent Statistics released by World Health Organization (WHO), In the United Kingdom and theUnited States, the percentages of men undergone this procedures are about 20% and 13% respectively. In European countries such as France, this procedure is also common. It is allowed since 2001 to permanently cutting the vas deferens that carries sperm to the prostate.
Previous studies have explored the eventual connection between sterilization by vasectomy and the occurrence of prostate cancer. But the results, due to little homogeneity, appear contradictory. But another study Initiated in 1986 by the team of Dr. Lorelei Mucci (Harvard School of Public Health, Boston) which included 49,400 men aged 40-75 years has shed more light. In 2000, 25% of them (the 49,400 men) had voluntarily undergone a vasectomy for contraceptive purposes.
The Results? Fetal Cases of Prostate Cancer Increased
At the end of follow-up in 2010, prostate cancer was diagnosed in 6023 of these 49,400 men (12.2%). Of these, 732 had a high grade cancer. A total of 811 cases were fatal. 24-year follow-up,”the cumulative incidence of serious forms of prostate cancer was 1.6%. Considering the risks, the absolute risk is only slightly increased after a vasectomy”, the researchers said.
Of all cases of prostate cancer, men who had a vasectomy have a 10% risk in addition to developing cancer, compared to those who did not undergo a permanent contraception.
Vasectomy was specifically associated with increased risk of advanced and fatal prostate cancer, with an increase of 20% and 19% respectively. The risk of high grade cancer, Gleason score 8 to 10, alsorecorded an increase of 22%. However, no significant relationship was observed between vasectomyand the risk of low-grade or localized prostate cancer.
Note: according to Gleason score6 is a low-grade cancer, 7 is a medium-grade cancer, and a score of 8, 9, or 10is a high-grade cancer.
No Linkwith Screening and Prostate Cancer
Additional analysis was performed on a subgroup of nearly 14,000 men who regularly used ascreening for prostate cancer with Prostate-specific antigen (PSA). Among these individuals, the risk of high grade cancer after vasectomy is even higher, with an increase of 28%. The risk of developingfatal prostate cancer is also increased, from 19% to 56%.
“The correlation between prostate cancer and vasectomy is still observed in patients screened, the increased risk of prostate cancer cannot be explained through the diagnosis,” said the researchers. But the increased risk of cancer could indeed be related to more frequent screening in patientsopting for vasectomy.
To identify potential risk factors and explore other ways, the influence of sex hormones, sexually transmitted infections or type of cancer treatment administered was assessed. No correlation couldbe demonstrated.
Importance to Understand theUnderlying Mechanisms
“It is necessary to better understand the potential underlying mechanisms contributing to increase the risk of the disease after vasectomy”, said Dr. David Miler, Department of Urology the University of Michigan, Medscape Medical News. The risk of prostate cancer of high grade and fatal evolution arecertainly higher after permanent vasectomy, “but it is ultimately an absolute risk for about 1%; this is very low, “said the urologist.
According to Dr. David Miler, given the contradictions that the study currently presents, the literaturecannot be referred to discourage men who envisage who consider to undergoing a vasectomy,particularly because of the lack of clarity to identify other potential causes of the increase.
“The results of this study call for further research to clarify the association between prostate cancerand vasectomy,” the authors concluded.
- Siddiqui Minhaj M, Wilson K, Epstein M, Massoubre C. Vasectomy and risk of aggressive prostate cancer : a 24-year follow-up study. Journal of Clinical Oncology ; publication en ligne du 7 juillet 2014