On 22 December 2016, the Journal of the Royal Colleges of Surgeons of Edinburgh and Ireland published online a large population-based study corroborating longstanding clinical knowledge that non-therapeutic circumcision puts boys at markedly elevated relative risk of USD (urethral stricture disease), including meatal stenosis (narrowing of the urinary outlet). The study found a 10-26 fold increase in the incidence of meatal stenosis and a 5-14 fold increase in other USDs in circumcised boys compared to genitally intact boys, suggesting a considerable clinical and economic impact. The authors, Danish epidemiologists Morten Frisch and Jacob Simonsen, estimate that “at least 78% but more likely around 89%–93%” of USD cases in the United States may be attributable to circumcision.

The full article is available at: http://www.thesurgeon.net/article/S1479-666X(16)30179-2/fulltext.

Abstract

Background

Meatal stenosis is markedly more common in circumcised than genitally intact males, affecting 5–20 per cent of circumcised boys. However, no population-based study has estimated the relative risk of meatal stenosis and other urethral stricture diseases (USDs) or the population attributable fraction (AFp) associated with non-therapeutic circumcision.

Methods

In two nationwide cohort studies (comprising 4.0 million males of all ages and 810 719 non-Muslim males aged 0–36 years, respectively), we compared hospital contact rates for USD during 1977–2013 between circumcised and intact Danish males. Hazard ratios (HRs) were obtained using Cox proportional hazards regression, and the AFp estimated the proportion of USD cases in <10 year-old boys that is due to non-therapeutic circumcision.

Results

Muslim males had higher rates of meatal stenosis than ethnic Danish males, particularly in <10 year-old boys (HR 3.44, 95 per cent confidence interval 2.42–4.88). HRs linking circumcision to meatal stenosis (10.3, 4.53–23.4) or other USDs (5.14, 3.48–7.60) were high, and attempts to reduce potential misclassification and confounding further strengthened the association, particularly in <10 year-old boys (meatal stenosis: 26.3, 9.37–73.9; other USDs: 14.0, 6.86–28.6). Conservative calculations revealed that at least 18, 41, 78, and 81 per cent of USD cases in <10 year-old boys from countries with circumcision prevalences as in Denmark, the United Kingdom, the United States and Israel, respectively, may be attributable to non-therapeutic circumcision.

Conclusion

Our study provides population-based epidemiological evidence that circumcision removes the natural protection against meatal stenosis and, possibly, other USDs as well.

 

Frisch M, Simonsen J. Cultural background, non-therapeutic circumcision and the risk of meatal stenosis and other urethral stricture disease: two nationwide register-based cohort studies in Denmark 1977–2013. Surgeon. Published online 22 Dec 2016. DOI: http://dx.doi.org/10.1016/j.surge.2016.11.002