Endogenous sex hormones and prostate cancer: a quantitative review of prospective studies

This paper presents a quantitative review of the data from eight prospectiv e epidemiological studies, comparing mean serum concentrations of sex hormo nes in men who subsequently developed prostate cancer with those in men who remained cancer free. The hormones reviewed have been postulated to be inv olved in the aetiology of prostate cancer: androgens and their metabolites testosterone (T), non-SHBG-bound testosterone (non-SHBG-bound T), di-hydrot estosterone (DHT), androstanediol glucuronide (A-diol-g), androstenedione ( A-dione), dehydroepiandrosterone sulphate (DHEAS), sex hormone binding glob ulin (SHBG), the oestrogens, oestrone and oestradiol, luteinizing hormone ( LH) and prolactin. The ratio of the mean hormone concentration in prostate cancer cases to that of controls (and its 95% confidence interval (CI)) was calculated for each study, and the results summarized by calculating the w eighted average of the log ratios. No differences in the average concentrat ions of the hormones were found between prostate cancer cases and controls, with the possible exception of A-diol-g which exhibited a 5% higher mean s erum concentration among cases relative to controls (ratio 1.05, 95% CI 1.0 0-1.11), based on 644 cases and 1048 controls. These data suggest that ther e are no large differences in circulating hormones between men who subseque ntly go on to develop prostate cancer and those who remain free of the dise ase. Further research is needed to substantiate the small difference found in A-diol-g concentrations between prostate cancer cases and controls.