Washington, June 16 : Older men opting for testosterone replacement therapy, owing to their low testosterone levels, don't face an elevated risk of prostate cancer, says a new study.
According to lead author Aksam Yassin, MD, PhD, of the Clinic for Urology and Andrology of the Segeberger Clinics in Norderstedt, Germany, prostate cancer is a concern regarding testosterone therapy in older men.
"Testosterone treatment stimulates the growth of an existing prostate cancer, but there is no evidence that it causes this type of cancer," he said.
Yassin said, as the risk of prostate cancer and testosterone deficiency is know to increase with age, it is possible that a prostate cancer may occur in an older man during testosterone replacement therapy, which is unrelated to treatment.
His research, involving 154 testosterone-deficient men with an average age of 56, who had 1 to 3 years of follow-up testing, was aimed at determining if prostate cancer occurs more often with testosterone replacement therapy in men over 50.
The patients received testosterone injections in a hospital clinic in Bremerhaven, Germany. Testosterone was a slow-release form called testosterone undecanoate (brand name Nebido) that is not yet available in the United States. The researchers compared these patients with 160 men visiting the clinic for a health checkup who had normal testosterone levels and did not receive testosterone treatment. Their average age was 58.
All subjects had an evaluation that included a digital rectal exam, ultrasound measurement of prostate volume and a blood test for prostate-specific antigen (PSA), at the beginning of the study and then every 3 months afterward.
Increased PSA levels may indicate prostate cancer, an enlarged prostate or inflammation of the prostate (prostatitis). In case a man's PSA level was high-over 4 (micrograms per liter)-or otherwise abnormal, he underwent a prostate biopsy.
The rectal exam found no abnormalities. Eleven men receiving testosterone had a biopsy, two of which showed a small cancerous tumor on one side of the prostate. A third man was found to have a high-grade (more aggressively malignant) prostate cancer that had not yet spread to other organs.
Out of the 12 men in the untreated group, five had prostate cancer. Four of these tumors were on both sides of the prostate and were high grade. Thus, Yassin concluded that there were no more prostate cancers in the group that received testosterone treatment. He also said that the men receiving testosterone had smaller, less aggressive tumors than did the other men.
"There is increasing evidence that testosterone replacement therapy in testosterone-deficient men can improve their symptoms, such as decreased bone and muscle mass and low sex drive and depression. In view of the many benefits of treatment and the results of our study, we believe it is acceptably safe to treat older men with testosterone if there is a good reason for treatment," he said.
The results will be presented at The Endocrine Society's 90th Annual Meeting in San Francisco.