PURPOSE: We investigated whether dynamic patterns of testosterone levels contribute to risk of prostate cancer.
MATERIALS AND METHODS: We used data on 376 untreated men with hypogonadism (testosterone 12.1 nmol/l or less) recruited from a urology office in Germany. Age at study entry served as a surrogate for age at the first detection of testosterone below 12.1 nmol/l. We derived 3 indicators, including the coefficient of variation, the ratio of the largest decline relative to the mean and the median of maximum declines, to measure the dynamic patterns of testosterone in an individual.
RESULTS: Our findings suggest that the later that testosterone dropped below 12.1 nmol/l in a man, the less the lifetime risk of prostate cancer in that individual (HR 0.68, 95% CI 0.57-0.82). Further declines or dynamic variations of testosterone were associated with increased risk of prostate cancer (high vs low coefficient of variation HR 4.88, 95% CI 1.97-12.08, high vs low ratio of largest decline relative to mean HR 8.45, 95% CI 2.82-25.37 and high vs low median of maximum declines HR 2.70, 95% CI 1.15-6.35).
CONCLUSIONS: To our knowledge this study is the first to provide evidence of the association between dynamic patterns of testosterone and prostate cancer development. This may have substantial clinical impacts on prostate cancer prevention.