The highly protective effect of newborn circumcision against invasive penile cancer.

OBJECTIVE We determined the relation between newborn circumcision and both invasive penile cancer (IPC) and carcinoma in situ (CIS) among adult male members of a large health maintenance organization. SUBJECTS AND METHODS Circumcision status was ascertained by a combination of pathology reports, medical record review, and questionnaires for 213 adult male members of a large prepaid health plan who were diagnosed with IPC or CIS. RESULTS Of 89 men with IPC whose circumcision status was known, 2 (2.3%) had been circumcised as newborns, and 87 were not circumcised. Of 118 men with CIS whose circumcision status was known, 16 (15.7%) had been circumcised as newborns. CONCLUSIONS Our results confirm the highly protective effect of newborn circumcision against IPC and the less protective effect against CIS.