Goserelin acetate and flutamide versus bilateral orchiectomy: a phase III EORTC trial (30853). EORTC GU Group and EORTC Data Center

Abstract

Maximal androgen blockade (MAB), the eradication of the effects of adrenal androgens on prostate cancer cells after castration, has been used with differing success in the treatment of prostatic carcinoma. The aim of this randomized phase III study was to compare the efficacy and side effects of bilateral orchiectomy versus a combination of a luteinizing hormone-releasing hormone agonist (LHRH-A) depot formulation, goserelin acetate (3.6 mg s.c. once every four weeks), and flutamide (250 mg three times daily), in patients with metastatic cancer. Treatment usually continued until disease progression (or for a minimum of three months). Efficacy was assessed by response, time to disease progression, and duration of survival. Clinical evaluations, standard laboratory tests, and imaging examinations were carried out regularly. A total of 327 patients were entered in this study. There was a difference in response only for prostatic acid phosphatase (PAP) with a more frequent decrease of the serum values to normal in the serum in patients assigned to MAB treatment. The MAB treatment, however, proved significantly better for time to subjective progression, time to objective progression, time to first (subjective and objective) progression, and duration of survival. The most frequent side effects for both treatments included hot flushes and gynecomastia. In conclusion, significant time to progression and survival benefits are achieved by adding flutamide to an LHRH-A regimen, probably improving the quality of life of patients with metastatic cancer.