Time course of serum testosterone and luteinizing hormone levels after cessation of long-term luteinizing hormone-releasing hormone agonist treatment in patients with prostate cancer

INTRODUCTION. In order to elucidate the influence of hormone-releasing hormone (LHRH) agonist therapy cessation on pituitary/testicular function and its clinical implications, we investigated prospectively hormonal (luteinizing hormone: LH; testosterone: T) responses in patients with prostate cancer who received long-term LH-RH 10 agonist therapy. PATIENTS AND METHODS. A consecutive 32 patients who had received LH-RH agonist therapy over 24 months were enrolled. As a baseline, T and LH were measured at the time of LHRH agonist therapy cessation, monthly for 3 months, and subsequently, every 3 months. RESULTS. The median duration of LH-RH agonist therapy was 30 months (24-87 months) with median follow-up duration of 24 months following cessation. All patients had castrated T levels and suppressed LH levels at baseline. Median duration of castrated T levels following cessation was 6 months. Median time to normalization of T levels was 24 months. LH levels returned to normal within 3 months in all cases. Patients who received androgen deprivation therapy for 30 months or longer required a longer time for recovery of T levels. Patients over 65 years of age showed a statistically significant longer time for recovery of T levels (P = 0.0167). CONCLUSIONS. Long-term LH-RH agonist therapy has remarkable effects on serum T level that last for a significant time after cessation, a fact that should be applied to the interpretation of both PSA and serum T levels after cessation of androgen deprivation therapy.