The conclusions of separate studies presented at the American Urological Association annual meeting show no association between testosterone replacement therapy and the increased likelihood of prostate cancer [PCa]. In fact, the study concluded that testosterone treatment might even lower the risk of prostate cancer and protect against the most aggressive forms of the disease.
Researchers at the University of Washington studied 147,593 veterans with low total testosterone and found that the incidence of PCa (per 1,000 person-years) was lower (2.27) among men who ever received testosterone treatment and higher (2.60) among those who had never received testosterone. Of the men who had received treatment, 40% received intramuscular testosterone only, 38% received topical testosterone only, and 22% received both types. The study found no association between testosterone therapy and PCa risk regardless of testosterone formulation or dosage.
“Among veterans with low testosterone levels, compared to no treatment, testosterone treatment was not associated with increased risk of subsequent prostate cancer diagnosis, any prostate cancer or high grade,” said principal researcher Dr. Thomas Walsh of the University of Washington, Seattle.
In another study, urologist Ahmad Haider, MD, and his colleagues found that long-term treatment with testosterone was associated with a lower incidence of PCa and less aggressive PCa. The study comprised 656 men with low total testosterone. Of these subjects, 360 had received testosterone therapy and the remaining 296 who had opted against treatment served as controls.
PCa was diagnosed in 7 men (1.9%) in the testosterone group and 12 men (4.1%) in the control group. The incidence of PCa per 10,000 patient-years was 30.0 in the testosterone group versus 63.5 among controls.
As a result of his research, Dr. Haider concluded that “Long-term treatment with testosterone in hypogonadal men may reduce the incidence of prostate cancer and protect against high-grade prostate cancer”.
As with all fields of study more research is needed, but these findings undoubtedly turn-the-tables on a long-held assumption.