Treatment of advanced breast cancer with norethisterone acetate.

The medical records of 84 postmenopausal women treated with oral norethisterone acetate (NTA) for advanced breast cancer were retrospectively analyzed. Treatment was devoid of significant toxicity. Twenty-one patients were not evaluable for treatment response either because of insufficient data or inadequate treatment trial. Complete plus partial response was obtained in 21 (33.3%) of the 63 evaluable patients, with a median duration of 10 months. Disease stabilization was observed in 16 (25.4%) patients for a median duration of 5 months, while 26 patients (41.3%) showed progressive disease while on treatment. The best response was observed in women with dominant soft part disease and an age over 70 (CR+PR 48%). The literature on norethisterone acetate is reviewed and compared with present results. The role of progestational agents in the treatment of advanced mammary carcinoma is discussed.