Objective: In a cross-sectional, retrospective, non-randomised study to investigate the possibility that some patients treated with luteinizing hormone releasing hormone analogues (LHRH analogues) fail to reach castration levels of serum testosterone.
Methods: 40 patients treated with a 3-monthly formulation of leuprolide acetate and continuous use of an oral antiandrogen ("Leu group") and 25 patients treated with a 3-monthly formulation of goserelin acetate and an oral antiandrogen for one month ("Gos group") were identified from our hospital's registry. Serum testosterone was measured during treatment with the respective LHRH-analogue and compared between the two groups. In the Leu group, serum testosterone was measured during week 11 or 12 of treatment. In the Gos group, serum testosterone was assessed during week 23 or 24.
Results: Four patients (10%) treated with leuprolide acetate failed to reach the castration level of serum testosterone after treatment with one injection of a three-monthly formulation of leuprolide acetate. All patients treated with goserelin acetate achieved the castration level.
Conclusion: Although the overwhelming majority of prostate cancer patients during treatment of LHRH analogue achieve serum testosterone values within the castration range, individual patients may fail to reach this therapeutic goal, probably more often during treatment with leuprolide acetate than with goserelin acetate.