Poor response of breast cancer to tamoxifen.

Fifty eight (58) patients with early breast cancer (mean age 78.3 years) and 37 patients with advanced breast cancer (mean age 65.9 years) were treated with tamoxifen orally 20 mg daily or twice daily. The mean follow-up time was 19.1 months in the early group and 18.4 months in the late group. The drug was extremely well tolerated. All patients had cytological or histological evidence of breast cancer. A complete or partial response was found in only 36% of the patients with early breast cancer and only 13% in the advanced group. We conclude that tamoxifen was disappointing as a primary therapy in our patients. Although because of its lack of toxicity it can be seen as initial therapy for patients with breast cancer, it may have to be supplanted rapidly by other forms of therapy in the substantial proportion of patients in whom a response will not occur.