Individual variation of hormonal recovery after cessation of luteinizing hormone-releasing hormone agonist therapy in men receiving long-term medical castration therapy for prostate cancer.

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.