To assess whether a long-term follow-up shows any reduction in the level of luteinizing hormone (LH) secretion, which could result in declining testosterone levels in men with localized prostate cancer, as most (96%) men have testosterone levels within the normal range by 1 year after treatment with a short course of LH-releasing hormone analogue (LHRHa) and radiotherapy, and LH and follicle stimulating hormone (FSH) remain high at 1 year after treatment, maintaining the testosterone levels.
PATIENTS AND METHODS
We prospectively evaluated 55 patients who previously had a short course of LHRHa (median 97 days, range 28–167) and radiotherapy for localized prostate cancer. Eligible patients had documented normal testosterone, LH and FSH levels at baseline and at 1–3 years after radiotherapy. LH, FSH and testosterone were then measured at 5 years after treatment.
The mean hormone levels before, at 1–3 years and at 5 years after treatment, respectively, were: testosterone (nmol/L), 15.33, 13.98, 12.97; LH (U/L), 5.51, 9.95, 6.95; and FSH (U/L), 7.95, 22.40, 17.00. The decrease in testosterone level at 5 years vs 1–3 years was not statistically significant and was of little clinical relevance (P = 0.057). LH and FSH levels were higher at 1–3 years than at baseline and decreased significantly (P < 0.001) at 5 years towards the baseline value. The decrease in FSH level was less marked than for LH.
After a short course of LHRHa and radiotherapy, the testosterone level was maintained at 5 years. LH levels decreased towards the baseline value, suggesting recovery of Leydig cell function. FSH levels remained high, suggesting persistent Sertoli cell damage from treatment.