Maintaining healthy levels of testosterone (T) may decrease a man's risk of developing not only prostate cancer, but also other metabolic conditions, according to new research being presented at the 111th Annual Scientific Meeting of the American Urological Association (AUA). These data, which review the use of testosterone replacement therapy (TRT) in men with clinically proven low T, will be shared with media during a special press conference on Saturday, May 7, to be moderated by Dr. Stacy Loeb, a member of the AUA Public Media Committee.

Studies to be presented:

Relationship of Testosterone Treatment and Incident Prostate Cancer Risk Among U.S. Veterans with Low Serum Testosterone (Abstract MP04-04):

Testosterone treatment was not associated with an increased risk of prostate cancer diagnosis, according to researchers at the VA Puget Sound Healthcare System in Seattle. Researchers reviewed data on a cohort of 157,312 veterans with clinically confirmed low testosterone, and found that, among the 60,359 who received TRT (via transdermal application or intramuscular injection), prostate cancer incidence rate per 1,000 was 2.27, compared to 2.6 in men who had never received testosterone replacement.

Prostate Cancer is Less Frequent and Severe in Hypogonadal Men Treated Adequately with Testosterone Undecanoate Injections for up to 8 Years Compared to Untreated Hypogonadal Controls (Abstract PD09-04):

TRT in hypogonadal men may provide a protective effect against not only prostate cancer, but also high-grade disease, according to a new registry study from researchers in the United States and Germany. Comparing data from 360 men who were treated with testosterone to a control group of 296 men who were not treated, researchers found that, despite an initial increase in prostate volume and prostate-specific antigen (PSA) levels in the treatment group, seven cases of prostate cancer were diagnosed in the treatment group (incidence: 30.5 per 10,000) compared 12 cases in the control group (incidence: 63.54 per 10,000). The hypogonadal men treated with testosterone had lower grade tumors, with a predominant Gleason 3 with negative surgical margins and no lymph node involvement.

Cardiovascular Events and Prostate Cancer Diagnoses in Men Treated with Testosterone Replacement Therapy (Abstract PD50-03):

TRT may decrease risk for prostate cancer diagnoses, cardiovascular (CV) events and overall mortality, and this reduction in risk could be dose-responsive. Toronto researchers examined a cohort of men aged 66 and older with low T who were treated between 2007 and 2012 in Ontario and found that, when compared to controls, patients with the lowest cumulative dose exposure had higher risks for CV events (including myocardial infarction, cerebrovascular accidents and venous thromboembolism) and overall mortality, and that patients with the highest dose exposure had decreased risks for prostate cancer diagnosis, CV events and overall mortality.

Testosterone Therapy and Prostate Cancer Risk (Abstract PI LBA 03):

Men being treated with TRT were more likely to present with favorable-risk prostate cancer and a lower risk of aggressive disease when compared to men who did not supplement, according to an analysis of data from the National Prostate Cancer Register (NPCR) and the Prescribed Drug Register in Sweden. Researchers in Sweden and New York reviewed prostate cancer cases in men on TRT therapy and found no significant association between use of TRT and overall prostate cancer risk, but observed an increased risk of favorable risk disease within the first year of TRT (possibly due to detection bias) as well as a lower risk for aggressive disease after more than one year of TRT use.

Effects of Testosterone Replacement Therapy on Lower Urinary Tract Symptoms: A Systematic Review and Meta-Analysis (Abstract PD22-04):

Lower urinary tract symptoms (LUTS) do not necessarily worsen in men with late-onset hypogonadism being treated with TRT, according to a multi-institutional study from researchers in Houston, Boston and Miami. Using a review of literature published between 1977 and 2015 in the MEDLINE, EMBASE and Cochrane Library databases, data from 14 randomized, controlled trials involving 2,029 participants was analyzed to assess International Prostate Symptom Scores (IPSS) in hypogonadal men. Data review showed that IPSS scores were similar in those men with low T who received TRT and those with untreated low T.

"These studies all provide evidence for potential protective effects of testosterone therapy in men with clinically diagnosed low testosterone and underscore the importance of maintaining healthy levels of this hormone," said Dr. Loeb. "At the same time, another key message here is that there may be real risks to letting hypogonadism go untreated."