This retrospective study of the extended Oregon Series (1940 to 1965) of patients with breast cancer, first reported in 1961, compares the now long-term results of treatment of pathologic stage T2/3 NO breast cancers with intent to cure by the following two en bloc ablative operative procedures of variable extent and completeness: standard radical mastectomy vs ultraradical mastectomy. The extent and completeness of the en bloc procedure are shown again to be critical determinants of local control and survival. The local recurrence rate for standard radical mastectomy is 12.4% (8/70) and for ultraradical mastectomy it is 0% (0/78). Proportionate survival at 20 years for standard radical mastectomy was 59.8% (95% confidence limits, 0.598 +/- 0.14) and for ultraradical mastectomy it was 98.1% (95% confidence limits, 0.981 +/- 0.04).