Is it true that circumcision protects against penile cancer and HPV?

Circumcision at a young age is associated with a clearly lower risk of invasive penile cancer: a meta-analysis of three case-control studies found an odds ratio of 0.33, which amounts to roughly 67% less risk. That sounds impressive, but there is an important nuance: once men with a tight foreskin (phimosis) were excluded, the protective effect disappeared in two of those studies. Part of the protection may therefore run through the prevention of phimosis, rather than through circumcision itself.

For early precursor stages of penile cancer, in which the surface cells are already abnormal but have not yet grown deeper, no protective effect was found, regardless of the age at circumcision. Circumcision in adulthood even showed a possible increased risk in the same analysis, although that was statistically uncertain. A selection effect is the likely explanation: men who are circumcised as adults sometimes do so precisely because of existing penile problems that are themselves already a risk factor.

HPV is involved in approximately 40% of all penile cancer cases. Whether circumcision protects against HPV infection is less clear-cut. A modest protective effect has been described, but the absolute benefit is small. According to a comprehensive review, good hygiene and safe sex have a far greater impact than routine circumcision. Adequate penile hygiene combined with access to clean water can largely eliminate the elevated risk of penile cancer in uncircumcised men.

Circumcision also carries risks. The chance of an acute complication (such as bleeding or infection) is around 1%, and a proportion of boys later require a repeat operation. The risk decreases with an experienced practitioner and adequate pain management. This means that the choice for or against routine circumcision requires weighing a modest and partly indirect benefit for cancer prevention against the surgical risk.