The Strong Protective Effect of Circumcision against Cancer of the Penis

Abstract

Male circumcision protects against cancer of the penis, the invasive form of which is a devastating disease confined almost exclusively to uncircumcised men. Major etiological factors are phimosis, balanitis, and high-risk types of human papillomavirus (HPV), which are more prevalent in the glans penis and coronal sulcus covered by the foreskin, as well as on the penile shaft, of uncircumcised men. Circumcised men clear HPV infections more quickly. Phimosis (a constricted foreskin opening impeding the passage of urine) is confined to uncircumcised men, in whom balanitis (affecting 10%) is more common than in circumcised men. Each is strongly associated with risk of penile cancer. These findings have led to calls for promotion of male circumcision, especially in infancy, to help reduce the global burden of penile cancer. Even more relevant globally is protection from cervical cancer, which is 10-times more common, being much higher in women with uncircumcised male partners. Male circumcision also provides indirect protection against various other infections in women, along with direct protection for men from a number of genital tract infections, including HIV. Given that adverse consequences of medical male circumcision, especially when performed in infancy, are rare, this simple prophylactic procedure should be promoted.

Figure 1

Prevalence of HPV in different histological types of squamous cell carcinoma of the penis. Bars indicate 95% confidence intervals. Modified from Miralles-Guri et al. [9].

Figure 2

Difference in prevalence of high-risk HPV types between circumcised and uncircumcised men.

Figure 3

The circumcised and uncircumcised penis, depicting the differences in prevalence of HPV between each.

Figure 4

Fixed effects forest plot models of the unadjusted risk ratios for (a) any high-risk HPV and for (b) multiple high-risk HPV infections detected at the coronal sulcus/glans in circumcised and uncircumcised men. The data are derived from both observational studies and randomized trials, and include HPV prevalence and incidence estimates. The unadjusted risk ratios differ from the adjusted odds ratios reported in some studies, because the odds ratio does not approximate to the risk ratio with common disease outcomes such as HPV, and because adjustment for risk behaviors may affect estimates. Nevertheless, the findings are in general consistent across studies as indicated by the nonsignificant tests for heterogeneity and suggest that, in aggregate, circumcision may reduce any high-risk HPV infection by approximately 36%, and multiple high risk HPV infections by 57%.