Sexual behaviour, history of sexually transmitted diseases, and the risk of prostate cancer: a case-control study in Cuba.

ABSTRACT

BACKGROUND: The relationship between the risk of prostate cancer and sexual activity and history of sexually transmitted diseases was investigated in a case-control study conducted in Cuba aimed at assessing the effect of lifestyle and environmental factors, as well as hormonal and genetic factors, on the occurrence of this disease. METHODS: During the period 1998-2000, all men up to 84 yr old with newly diagnosed, cytologically and/or histologically confirmed prostatic cancer who were resident in Havana City were identified in nine major hospitals in the area. Controls were resident in the same city, frequency-matched by age (+/-5 years) and hospital. The study included 273 cases and 254 controls. Information was obtained through an interview. RESULTS: The risk of prostate cancer was increased among men with a history of venereal disease (odds ratio = 1.7, 95% CI = 1.1-2.5). A higher frequency of cases reported having had sex with prostitutes, although the estimate of relative risk did not reach statistical significance. Similarly, a nonsignificant positive association was found with the number of female sexual partners. A significant increased risk was observed in subjects who reported having sexual intercourse more than 7 times per week compared with those who reported a weekly frequency of 3 times or fewer (odds ratio = 2.1, 95% CI = 1.2-3.7). Moreover, a significant trend was demonstrated. CONCLUSIONS: The study supports the hypothesis that an infectious factor related to sexual behaviour could be involved in the occurrence of prostate cancer. A role for hormonal factors related to sexual activity cannot be ruled out.