Objective: 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.
Results: 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.
Conclusion: 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.