I ran across this and thought some of you guys might be interested…
[quote]It is well-known that the treatment of metastatic prostate cancer involves depriving the cancer of testosterone. This would imply that testosterone is a tumor-promoter and would predict that prostate cancer risk should be increased in men with higher levels of testosterone.
The increased risk of prostate cancer in black men has been used to support this hypothesis given that black men tend to have higher serum testosterone levels than white men. Fear of the tumor-promoting effects of testosterone has been one of the arguments used against routine testosterone replacement in older men with hypogonadism.
Furthermore, the capacity of finasteride, a drug that inhibits the conversion of testosterone to dihydrotestosterone, to reduce the risk of prostate cancer about 25% over 7 years adds more weight to the hypothesis that endogenous androgen levels contribute to the risk of prostate cancer.
At least 18 studies have attempted to assess a relationship between endogenous androgen hormone levels and prostate cancer, but the results have been equivocal.
Therefore, the Endogenous Hormones and Prostate Cancer Collaborative Group was composed of investigators who had previously published on the association of endogenous hormones and prostate cancer; data were pooled on nearly 4,000 men with prostate cancer and 6,500 controls and analyzed for risk of prostate cancer as a function of endogenous hormone levels.
No associations were found between the risk of prostate cancer and serum concentrations of testosterone, calculated free testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, androstenedione, androstanediol glucuronide, estradiol, or calculated free estradiol.
We seem to have here what Thomas Huxley called “the slaying of a beautiful hypothesis by an ugly fact.” Given the evidence that testosterone levels are not a risk factor for prostate cancer, it is essential to derive new hypotheses on the origin of that disease.
Furthermore, it may be possible to tentatively move forward in the treatment of certain conditions in aging men by supplementing them with exogenous testosterone when their endogenous levels fall. Whether testosterone therapy increases the risk of prostate cancer is still not defined, but it should cease to be a contraindication to testosterone replacement therapy until some evidence is generated that it is harmful.[/quote]