Ten-year results from the National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trial evaluating the use of L-phenylalanine mustard (L-PAM) in the management of primary breast cancer.

Abstract

Between 1972 and 1974, patients were entered into a National Surgical Adjuvant Breast and Bowel Project (NSABP) trial to evaluate L-phenylalanine mustard (L-PAM) as an adjuvant to mastectomy in patients with primary breast cancer and pathologically positive axillary nodes. Overall, findings through 10 years of observation indicate an 8% difference in disease-free survival (DFS) (P = .06) and a 5% difference in survival (P = .4). Women less than or equal to 49 years of age who received L-PAM demonstrate a significant (P = .03) prolongation of DFS and a significant (P = .05) survival benefit compared with those who received a placebo. There is a 37% reduction in their mortality and a cumulative odds of survival of 1.67. In that age group, both those with one to three and greater than or equal to 4 positive nodes benefited, but the advantage was greater when there were fewer positive nodes. There was a significant (P = .009) reduction in mortality (64%) and a cumulative odds of survival of 3.25 in patients l...