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

In order to elucidate the influence of hormone‐releasing hormone (LH‐RH) 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 LH‐RH 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. © 2005 Wiley‐Liss, Inc.