Testosterone Therapy Not Found to Increase Prostate Cancer Risk

Testosterone therapy may actually inhibit the growth of aggressive prostate cancer.

Men taking prescription testosterone for over a year were found to have no overall increase in the risk of developing prostate cancer, a recent study found.

The analysis examined more than one-quarter million medical records of mostly white males in Sweden. The findings will be presented at the American Urological Association’s annual meeting in San Diego.

In addition not finding an overall increase in risk, researchers saw a 50% reduction in the risk of aggressive prostate cancer.

“Based on our findings, physicians should still be watching for prostate cancer risk factors — such as being over the age of 40, having African-American ancestry, or having a family history of the disease – in men taking testosterone therapy, but should not hesitate to prescribe it to appropriate patients for fear of increasing prostate cancer risk,” said lead study investigator Stacy Loeb, MD, MSc.

This concern over cancer risk is due to standard therapy drugs for advanced prostate cancer that dramatically reduce male hormones.

“But when used appropriately by men with age-related low testosterone who are otherwise healthy, testosterone replacement has been shown to improve sexual function and mood,” Loeb said.

During the study, researchers found that 38,570 men developed prostate cancer between 2009 and 2012. There were 284 of these men prescribed testosterone replacement therapy before being diagnosed with prostate cancer.

Their records were compared with 192,838 men who did not develop prostate cancer, of which 1378 had been on testosterone therapy.

Although the analysis initially showed an increase of 35% in prostate cancer among patients soon after they started therapy, the increase was found only in prostate cancers with a low risk of spreading.

Furthermore, the long-term reduction in aggressive prostate cancer was found only in men who used testosterone for more than 1 year.

The risk of disease did not differ between preparations, including mouth, gel patch, or injection.

“Overall, our study suggests that what is best for men's health is to keep testosterone levels balanced and within a normal range,” Loeb said.

Researchers suggest that men with symptoms and testosterone levels that are below 350 nanograms per deciliter, should seek medical advice on whether or not they should start a testosterone therapy regimen.

For future studies, researchers will determine why low testosterone levels could trigger aggressive prostate cancer and why normal levels could help protect against an aggressive form of the disease.