Adjuvant chemotherapy with and without tamoxifen in the treatment of primary breast cancer: 5-year results from the National Surgical Adjuvant Breast and Bowel Project Trial.

Abstract

In this National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trial, 1,891 women with primary operable breast cancer and positive axillary nodes were randomized between Jan, 1977 and May 1980 to receive L-phenylalanine mustard (L-PAM) and 5-fluorouracil (5-FU) either with or without tamoxifen (TAM)-PFT. This report presents life table probabilities, cumulative odds ratios, and P values for disease-free survival (DFS) and survival at yearly intervals through 5 years of observation (mean time on study, 72 months). When patients were examined overall without regard for any discriminant associated with outcome, ie, age, number of positive nodes, or tumor receptor status, there was a significant prolongation of DFS (P = .002), but not survival through the fifth postoperative year. The benefit was almost entirely restricted to those greater than or equal to 50 years with greater than or equal to 4 positive nodes. In that group there was a 66% greater chance of remaining disease free if PFT was re...