Long-term effectiveness of luteinizing hormone-releasing hormone agonist or antiandrogen monotherapy in elderly men with localized prostate cancer (T1-2): a retrospective study

Abstract

Aim: To evaluate the long-term effectiveness, side effects and compliance rates of two types of drugs (luteinizing hormone-releasing hormone [LHRH] agonist and antiandrogen) that were used individually to treat patients with localized prostate cancer (T1-2) at our institution.

Methods: Ninety-seven patients who were diagnosed in the period from April 1997 to January 2000 as having clinically localized prostate cancer (T1-2) received either LHRH agonist (leuprolide acetate 7.5 mg/month) monotherapy (group 1, n = 62) or antiandrogen monotherapy (group 2, n = 35; 18 received bicalutamide 50 mg q.d., 13 received nilutamide 150 mg t.i.d. and 4 received flutamide 250 mg t.i.d.). The mean age in both groups was 76 years.

Results: The mean follow-up time was (50.8 +/- 8.5) months in group 1 and (43.1 +/- 2.2) months in group 2. Prostate-specific antigen (PSA) levels rose in only 1 of the 62 patients (1.6%) in group 1, and in 20 of the 35 patients (57.1%) in group 2. In group 2, 10 of the 20 patients (50%) with increasing PSA levels were treated with LHRH salvage therapy, and eight (80%) responded. Hot flashes (54.8%) and lethargy (41.9%) were the most common side effects in group 1. In contrast, nipple-tenderness (40%) and light-dark adaptation (17.1%) were more often seen in group 2. Only 1 of the 62 patients (1.6%) in group 1 switched to another medication because of adverse side effects; whereas 8 of the 35 patients (22.9%) in group 2 did so.

Conclusion: Unlike antiandrogen monotherapy, LHRH agonist monotherapy provided long-term durable control of localized prostate cancer (T1-2). It can also be an effective treatment option for patients whose disease failed to respond to antiandrogen monotherapy. The limitations of our study are the lack of health outcomes analysis and a small sample size.