Controlled trial of tamoxifen as single adjuvant agent in management of early breast cancer. Analysis at six years by Nolvadex Adjuvant Trial Organisation.

A randomised controlled trial of tamoxifen as a single adjuvant agent after mastectomy for early breast cancer, reported on at an average follow-up of almost 2 years in 1983, has now been followed up to a maximum of 6 years. 1285 patients aged 75 or less were entered into the trial. Premenopausal women with positive axillary nodes and postmenopausal women with both positive and negative axillary nodes were randomised to receive either tamoxifen 10 mg twice daily for two years or to the untreated control group with systemic therapy reserved until the time of relapse. 46% of the trial population had primary tumour specimens assayed for oestradiol receptor (ER) content. There has been a highly significant prolongation of the disease-free interval in the tamoxifen-treated group followed by a highly significant reduction in death rate, with 45 (34%) fewer deaths observed in the treated group than in the control group. This benefit appeared to be independent of menopausal, nodal, or ER status.