William Derval AikenI; Vernon Eric DaCostaII
IDepartment of Surgery, Radiology, Anaesthesia, and Intensive Care Section of Surgery, Division of Urology Faculty of Medical Sciences University of the West Indies. Mona, Kingston, Jamaica. email@example.com
IIHugh Wynter Fertility Management Unit, Faculty of Medical Sciences, University of the West Indies. Mona, Kingston, Jamaica
A recent report of a 19% increased risk of death from prostate cancer (CaP) in men who have had a vasectomy (1) corroborates earlier reports suggesting an association (2, 3). This prospective study, involving 49 405 men with 24 years median follow-up, provides the strongest level of evidence to date suggesting a possible link between vasectomy and CaP and should not be ignored by policymakers, family planning boards, and service providers.
Previous studies have been inconsistent and the validity of any association was questioned mainly due to possible detection bias, as well as confounding by sexually transmitted infections. The robustness of the present study and the finding of an association with only advanced and lethal CaP, but not early CaP, suggest that if detection bias were present, it would be minimal and the outcome, therefore, is likely to be internally valid.
Although there would seem to be limited, external validity in extrapolating these study findings to the Caribbean given that its study population had a 25% prevalence of vasectomy and was constituted of mostly professional, Caucasian men, the study findings are actually relevant for the area in a number of ways. First, the Caribbean area has the highest reported mortality rate from CaP and no one would want to unwittingly promote a procedure that has been shown empirically to increase its risk of death; second, there has been an increase in the number of men requesting vasectomy in Jamaica, mostly from the young professional and middle class (4), and this is likely to be the case in other territories as well; and third, the national family planning board (NFPB, Kingston, Jamaica) has been actively encouraging men to take greater responsibility for their sexual and reproductive health and to be more directly involved in family planning. It is likely that men who are more involved in family planning decisions are more likely to consider having a vasectomy. Finally, "no-scalpel" vasectomy is encouraged by the NFPB and its website states that "there are no known long-term effects" of vasectomy (5).
Although there is, as yet, no known biologically-plausible mechanism by which a vasectomy should increase a man's risk of lethal CaP, the empirical evidence has shown that it does. Even if this turns out to be a non-causal association, at the very least, health care providers have a duty to immediately begin informing men considering vasectomy of the possible increased risk of death from CaP and to actively follow them after the procedure to ensure that it is diagnosed early should it arise.
On a broader scale, policymakers, family planning boards, and professional associations, such as the Caribbean Urological Association and the Jamaica Urological Society, may want to issue some kind of position statement on vasectomy so that men and their partners can make informed decisions.
1. Siddiqui MM, Wilson KM, Epstein MM, Rider JR, Martin NE, Stampfer MJ, et al. Vasectomy and risk of aggressive prostate cancer: a 24-year follow-up study. J Clin Oncol. Available from: www.ncbi.nlm.nih.gov/pubmed/25002716 Accessed on 7 July 2014.
2. Giovannucci E, Ascherio A, Rimm EB, Colditz GA, Stampfer MJ, Willett WC. A prospective cohort study of vasectomy and prostate cancer in US men. JAMA. 1993;269(7):873 - 7. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8426446 Accessed on 12 August 2014.
3. Giovannucci E, Tosteson TD, Speizer FE, Ascherio A, Vessey MP, Colditz GA. A retrospective cohort study of vasectomy and prostate cancer in US men. JAMA; 1993;269(7):878 - 82. Available from: www.ncbi.nlm.nih.gov/pubmed/8123059. Accessed on 12 August 2014.
4. DaCosta V, Lewis T, Wynter S, Harriott J, Christie L, Frederick J. Experiences of Jamaican men who have undergone no-scalpel vasectomy at the University of the West Indies. Open Access J Contraception; 2010. Available from: http://dx.doi.org/10.2147/OAJC.S12340 Accessed on 15 September 2014.
5. Jamaica National Family Planning Board. Available from: www.jnfpb.org/ Accessed on 12 August 2014.