SYPHILIS AND THE RISK OF PENIS CANCER

Background and Objectives: Until recently, syphilis was considered a m ajor cause of penis cancer. The possible role of syphilis was discarde d without much debate with the detection of certain of human papilloma viruses centrally involved in the etiology of penis cancer. Goals: To reevaluate the association between syphilis and penis cancer by using truly population-based cancer and syphilis data and to generate a more sound basis for judging the possible role of syphilis in the etiology of penis cancer. Study Design: Patients with epidermoid cancer of the penis, totalling 1,523, were diagnosed and reported to the Danish Can cer Registry from 1943 to 1990. Through linkage with the Danish Syphil is Registry, the impact of prior syphilis infection was evaluated in a case-control design using patients with colon cancer or stomach cance r as controls. Results: Depending on the criteria used to assess prior syphilis status, 3% to 5% of patients with penis cancer had had syphi lis before the cancer diagnosis. The corresponding proportions were 2% to 4% among patients with colon cancer and 2% to 5% among patients wi th stomach cancer. Logistic regression showed that patients with penis cancer did not have a syphilis history significantly more often than control cancer patients. Conclusion: Syphilis should be removed from t he list of possible causes of penis cancer.