Testosterone therapy and its influence on growth and malignancy of the prostate gland

Joel M. Kaufman, MD, Associate Clinical Professor, University Of Colorado, USA

With the availability of transdermal formulations, testosterone (T) supplementation therapy is becoming more popular, especially in older males. Consequently, concerns have arisen about safety, especially regarding the prostate gland. Androgens are involved in the growth of both benign prostatic hypertrophy (BPH) and prostate cancer (PC), although causation of these conditions is unclear. Androgens are required for the growth, maintenance and functional activity of prostate cells. Males castrated before puberty and those with androgen insensitivity syndromes do not develop BPH or PC. Epidemiologic studies show no consistent relationship between serum T levels and PC. Additionally, in radical prostatectomy series, men with low serum T levels have more aggressive disease. Precipitation of BPH by T supplementation is uncommon. Many series show only small changes in prostate volume, digital rectal exam, lower urinary tract symptoms and urinary flow rates with T replacement in older males. Further, PSA levels increase to a very small degree, even in older males followed up to 42 months. In large series, very few cases of PC have occurred in men treated with T. However, many experts have concluded that T replacement is contraindicated in the presence of PC. Older series showed that administering T to men with active PC leads to disastrous results. However, with widespread PSA screening and aggressive treatment, in the modern era men with early PC are usually cured, as shown by non-detectable PSA levels. Recent case reports show that men cured of PC who are truly hypogonadal can be treated carefully without activation of their cancer. Recently, T replacement in hypogonadal men at high risk for PC (by virtue of having PIN on prostate biopsy) was shown not to result in an increased risk of PC or PSA elevation.