Circumcised men have a lower risk of developing prostate cancer compared with uncircumcised men, according to study findings published today in the journal Cancer.
This latest finding adds to the list of possible health benefits of the procedure. A growing body of evidence suggests that circumcision protects men against sexually transmitted infections, including HIV infection. Scientists hypothesize that in men who are uncircumcised, tears in the thin, delicate lining of the inner foreskin may allow disease-causing microbes easier entry into the bloodstream, or that the moist environment under the foreskin may allow microbes to survive for longer periods.
Additionally, studies have linked some infectious agents with cancer. For example, a meta-analysis of 29 case-control studies has found that sexually transmitted infections are associated with an increased risk of prostate cancer. Infectious agents such as human papillomavirus and hepatitis C virus have been shown to increase the risk of certain cancers; in fact, scientists estimate that about 17% of cancers are likely caused by infections. Researchers hypothesize that in such cases, infections cause inflammation or cellular changes that may promote the development of cancer.
To examine whether circumcision might protect against the development of prostate cancer, Jonathan L. Wright, MD, of the University of Washington School of Medicine in Seattle, and his colleagues analyzed data on 1754 men with prostate cancer and 1645 controls from 2 population-based studies. They found that compared with uncircumcised men, men who were circumcised before they first had intercourse had a 15% reduction in the risk of developing prostate cancer. Most of the men had been circumcised shortly after birth.
“These data are in line with an infectious/inflammatory pathway which may be involved in the risk of prostate cancer in some men,” said Wright in a statement. “Although observational only, these data suggest a biologically plausible mechanism through which circumcision may decrease the risk of prostate cancer. Future research of this relationship is warranted,” he added.