The Effects of Long‐Term Androgen Deprivation Therapy on Penile Length in Patients with Prostate Cancer: A Single‐Center, Prospective, Open‐Label, Observational Study

Abstract

The adverse effects of long-term drug therapy for prostate cancer (PCa) can dramatically impact patient quality of life and are considered to be important factors when selecting treatment. To assess stretched penile length before and after long-term androgen deprivation therapy (ADT) for treatment of PCa. From January 2008 to June 2010 at a single institution, 39 consecutive patients without distant metastases who were elected to receive ADT as initial therapy for PCa were prospectively enrolled. Exclusion criteria were history of penile anomalies and/or trauma, and prior radical prostate surgery or radiation therapy. Erectile functions were evaluated at baseline according to the International Index of Erectile Function (IIEF). Vertically stretched penile length was measured every 3 months from the pubopenile junction to the meatus with a spring scale. After ADT, significant 3-month interval changes in stretched penile length were noted for up to 15 months (P < 0.001). The relationship between potency and penile shortening was not significant (P = 0.45). The mean patient age was 67.1 years. Before therapy, the mean stretched penile length was 10.76 cm. After 24 months of ADT, mean penile length had decreased to 8.05 cm. However, these changes plateaued after 15 months. Normal erectile function (EF) was reported by 41% of patients before therapy, while 10.5% reported normal EF at the 24-month follow-up. The relationship between potency and penile shortening was not significant. However, patients who preserved their potency tended to experience less penile shortening. The administration of luteinizing hormone-releasing hormone (LHRH) agonists induced significant decreases in penile length for only up to 15 months in the absence of the confounding effects of surgery and radiation.