ORLANDO – Long-term testosterone replacement therapy was not associated with an increased risk of prostate cancer in hypogonadal men in a longitudinal registry study.
Furthermore, long-term use of injectable testosterone undecanoate did not negatively affect voiding function or residual voiding volume, Dr. Ahmad Haider and his associates reported at the annual meeting of the American Urological Association.
Of 300 registry participants with a mean age of 57.7 years who were receiving 1,000 mg of parenteral testosterone undecanoate, 5 developed prostate cancer during 6 years of follow-up, for a lower-than-expected incidence rate of 39.4/10,000 patient-years, said Dr. Haider, a urologist in private practice in Bremerhaven, Germany, whose abstract was selected as a "best abstract" at the meeting.
Testosterone levels in the registry participants increased from 9.86 nmol/L to 17 nmol/L during the observation period, and prostate volume increased from 28.34 mL to 30.72 mL. Mean prostate specific antigen levels remained fairly stable over time, increasing from 1.77 ng/mL to 2 ng/mL during follow-up; those who experienced PSA increases of greater than 4 ng/mL were further evaluated for prostate cancer, Dr. Haider said.
Tumor stage among the prostate cancer patients was pT2a in 4 patients, and pT1b in 1 patient. Gleason score was 3+3 in 4 patients, and 3+2 in 1 patient. All of the prostate cancer patients underwent radical prostatectomy.
The mean International Prostate Symptom Score (IPSS) in the registry participants decreased significantly from 6.57 to 4.21, the residual voiding volume decreased significantly from 46.78 ml to 15.85 ml, the International Index of Erectile Function (IIEF) Erectile Function domain increased significantly from 20.01 to 26.11 (out of 30) with a plateau at 36 months, the Aging Males Symptoms scale (AMS) (a quality of life measure) improve significantly from 53.43 to 17.41 within the first 2 years, and weight and waist circumference decreased progressively by 16.8 kg, and 8.94 cm, respectively.
Improvements in lipid pattern, blood pressure, and glucose homeostasis were also observed, Dr. Haider said.
Registry participants were evaluated at baseline, after 6 weeks of therapy, and every 12 weeks thereafter for up to 72 months. Ultrasound measures of prostate volume and residual voiding volume were taken at every visit or every other visit. PSA was measured and the IPSS, IIEF-EF, and AMS questionnaires were administered at every visit.
Treatment adherence was excellent.
The anthropometric and metabolic parameters were assessed because prostatic diseases are closely associated with the metabolic syndrome, Dr. Haider explained.
The findings suggest that ongoing concerns about the safety of long-term testosterone replacement therapy may be unfounded. In this study, the incidence of prostate cancer did not suggest an increased risk, Dr. Haider said.
"Also, long-term treatment with testosterone undecanoate injections did not negatively affect voiding function as measured by IPSS, or residual postvoiding volume. Erectile function was markedly and sustainably improved. Part of these effects may be a result of parallel reduction in body weight and visceral fat measured by waist circumference, and other elements of the metabolic syndrome," Dr. Haider concluded.
This study was partially funded by Bayer Pharma AG.