Public release date: 29-Jan-2008

Sex hormones circulating in the blood do not appear to be associated with prostate cancer risk, according to data from 18 prior studies. The analysis will be published online January 29 in the Journal of the National Cancer Institute.

Having high levels of male sex hormones, known as androgens, has long been hypothesized as a risk factor for prostate cancer. Nearly two dozen prospective studies have examined the relationship between circulating sex hormones and prostate cancer risk, but the results have been inconsistent.

Andrew Roddam, D.Phil., of the University of Oxford in England and colleagues at the Endogenous Hormones and Prostate Cancer Collaborative Group collected the original data from 18 studies and analyzed it to determine the relationship between blood levels of sex hormones and prostate cancer. The pooled data included 3,886 men with prostate cancer and 6,438 controls.

The researchers found no association between prostate cancer risk and blood levels of different forms of testosterone or estrogen.

“The results of this collaborative analysis of the existing worldwide data on the associations between endogenous hormone concentrations and prostate cancer risk indicate that circulating concentrations of androgens and [estrogens] do not appear to be associated with the risk of prostate cancer,” the authors write.

In an accompanying editorial, Paul Godley, M.D., Ph.D., and colleagues at the University of North Carolina at Chapel Hill commend the authors for collaborating on this analysis, and they encourage researchers to use the results as an opportunity to shift the focus of prostate cancer research.

“The study obliges the scientific community to move past a seductive, clinically relevant, and biologically plausible hypothesis and get on with the difficult task of exploring, analyzing, and characterizing modifiable risk factors for prostate cancer,” the editorialists write.