Objective: To evaluate the process of hormonal recovery after cessation of luteinizing hormone-releasing hormone (LHRH) agonist treatment in patients who had received long-term LHRH agonist therapy for prostate cancer.
Material and methods: Men who had successfully undergone androgen deprivation therapy with only monthly LHRH agonist therapy for > 30 months were enrolled and the administration of LHRH agonist was discontinued. Serum total testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prostate-specific antigen (PSA) were measured before the cessation of LHRH agonist therapy and every 4 weeks thereafter, and the administration of LHRH agonist remained suspended until the total testosterone level recovered to > 50 ng/dl.
Results: Ten patients were enrolled in the study. The median (range) castration period and the levels of serum LH, FSH, total testosterone and PSA at cessation of therapy were 39 (30-56) months,<0.5 (<0.5-1.8) mIU/ml, 6.4 (3.0-15.9) mIU/ml, 15.3 (5.8-34.7) ng/dl and 0.13 (0.02-0.89) ng/ml, respectively. Testosterone recovered to > 50 ng/dl in all cases. There were large variations in the times required for recovery of LH and FSH (30-100 days) and serum testosterone (30-330 days). PSA began to increase at various testosterone levels, and there was a large variation (0-83%; median 41%) in the ratio of the androgen suppression (testosterone < 50 ng/dl) time to the period of LHRH agonist cessation.
Conclusions: There was considerable variation in the hypothalamus-pituitary-testicular hormone profiles during recovery from long-term medical castration. These findings are noteworthy when interruption of androgen deprivation therapy is applied with the intention of delaying the progression of hormone-refractory cancer or improving the patient's quality of life.