Prediagnostic serum hormones and the risk of prostate cancer.

Serum samples were obtained from 6860 men during their study examination from 1971 to 1975. After a surveillance period of about 14 years, 98 incident cases of prostate cancer were identified. Their stored sera and that of 98 matched controls from the study population were tested for the following: testosterone, dihydrotestosterone, estrone, estradiol, and sex hormone globulin. There was a suggestion that serum dihydrotestosterone levels were lower and the testosterone/dihydrotestosterone ratios were higher in the prostate cancer cases compared with their controls. However, none of these associations or that of the other hormones was strongly significant. Further work is needed to clarify the relationship between sex hormones and prostate cancer risk.