SAN ANTONIO—A study of hypogonadal men on testosterone replacement therapy (TRT) found no evidence of an increased risk of prostate cancer (PCa), researchers reported at the American Society of Andrology’s 2013 annual meeting.
These men did, however, experience weight loss, according to a separate analysis of the same cohort.
“Our evidence suggests that long-term testosterone replacement therapy in hypogonadal men is safe, provided that proper monitoring according to the guidelines is performed,” said Farid Saad, PhD, DVM, the first author of both studies. “And the majority of the men we studied were overweight or obese, so losing weight wasn’t deleterious for them. And 5% gained weight, but they had inflammatory bowel disease and were normal weight or slightly overweight at baseline, so it was beneficial for them to gain weight.”
Dr. Saad is Director of Global Medical Affairs Andrology, Bayer Pharma, Berlin, which funded the study and makes the form of testosterone the patients were on.
The investigations were open-label, prospective registry studies of 850 testosterone-deficient men. The men received 1,000 mg parenteral testosterone undecanoate six weeks after baseline and then every 12 weeks. They were treated for up to five years.
There were three separate cohorts, one from a university-based andrology center and two from urology centers. The andrology center cohort included 334 patients with a mean age of 42 years. One urology-center cohort consisted of 261 men with a mean age of 58 years, and the other included 255 patients with a mean age of 60.6 years.
The mean PSA in the first cohort increased from 1.8 to 1.9 ng/mL during the study period. For the other two groups, the respective increases were from 0.86 to 1.38 ng/mL and from 1.7 to 1.82 ng/mL. Their respective increases in average prostate volume were from 16.1 to 19.7 mL, 28.51 to 30.23 mL and 27.9 to 36.98 mL,.
The PCa incidence rates/10,000 patient-years in the three groups were 0%, 2.3% and 1.18%, respectively. These are significantly lower than the 116 and 96.6/10,000 patient-year rates reported, respectively, in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial (N Engl J Med 2009;360:1310-1319) and the European Randomized Study of Screening for Prostate Cancer (N Engl J Med 2012;366:981-990).
In the first and second cohorts, the International Prostate Symptom Score decreased from 10.35 to 6.58 and from 6.73 to 2.83, respectively (data unavailable for the third cohort), while post-void residual volume fell from 23.82 to 17.59 mL and from 46.61 to 19.74 mL, respectively.
In the youngest cohort, subjects’ mean body weight dropped from 106.22 to 90.07 kg. The middle cohort’s average body weight decreased from 100.15 to 92.46 kg, and the oldest group’s average weight fell from 103.0 to 79.1 kg.
The respective decreases in waist circumference were from 107.24 to 98.46 cm, 107.68 to 97.36 cm, and 114.0 to 94.1 cm. The body mass indices fell from 33.93 to 29.17 kg/m2, 31.75 to 29.32 kg/m2, and from 31.8 to 24.4 kg/m2, respectively.