Fears that testosterone replacement therapy may induce or promote prostate cancer are overblown, according to one leading urologist. The reality is that TRT can be a safe and effective treatment for hypogonadal men.

"There are no data to support testosterone as a cause for prostate cancer," said David Crawford, MD, of the University of Colorado Health Sciences Center in Denver. "It is time to reevaluate this notion."

The controversial concept that TRT may contribute to prostate cancer is based on shaky logic and a single report on a single patient, Dr. Crawford explained to colleagues at the Urology Congress yesterday.

The argument seems compelling: If castration kills prostate cancer, then boosting testosterone should have the opposite effect of promoting the disease.

The argument is also fallacious: Men dying of prostate cancer have already been deprived of testosterone, yet androgen deprivation therapy is known to fail in virtually all patients.

Dr. Crawford noted that the only investigational support for the idea that testosterone promotes prostate cancer is based on a 1941 report of equivocal acid phosphatase results in one patient. Data published since 2000 indicate that low testosterone is associated with a Gleason score of 8 or higher on biopsy. In men with localized disease, low testosterone is emerging as an independent predictor for extraprostatic disease.

In more recent testosterone treatment trials, investigators have found prostate cancer rates of about 1%, similar to the rate found by routine screening in the general population.

TRT trials reported to date are encouraging, Dr. Crawford noted, but not definitive. Sample sizes are small, selection bias is evident, follow-up periods are short, and trials have not been randomized. There is also a lack of basic research to support claims that TRT does or does not promote prostate cancer.

"There is documentation that you can use TRT," Dr. Crawford said. "It is safe with appropriate medical monitoring."

He recommended biopsy before initiating TRT and quarterly PSA testing and digital rectal exam for the first year. PSA and DRE can be scaled back to semiannually after the first year of therapy.