High-dose oral medroxyprogesterone acetate or tamoxifen as adjuvant hormone therapy for node-negative early-stage breast cancer: randomized trial with 7-year update.

A randomized adjuvant trial compared tamoxifen 20 mg daily for 5 years with high-dose oral medroxyprogesterone acetate (MPA) 1 g orally for 9 months. One hundred ninety-four patients with histologically proven primary node-negative breast carcinoma were enrolled between December 1990 and October 1996, with 98 patients randomized into the tamoxifen arm and 96 into the MPA arm. At a median follow-up of 86 months, 25 relapses and 13 deaths were recorded. The relapse-free survival rate at 7 years in the tamoxifen arm was 93%, versus 81% in the MPA arm (P = 0.02). The difference was observed in patients with stage T2 disease (100% in the tamoxifen group vs. 64% in the MPA group; P = 0.01), in younger and/or premenopausal patients (in patients < 50 years of age, 100% in the tamoxifen arm vs. 81% in the MPA arm [P = 0.02], and in patients > or = 50 years of age, 90% in the tamoxifen arm vs. 82% in the MPA arm [P = 0.16]). Also, the overall survival rate at 7 years was lower in women < 50 years of age (P = 0.04).