Doxorubicin-containing regimens for the treatment of stage II breast cancer: The National Surgical Adjuvant Breast and Bowel Project experience.

Abstract

Despite numerous reports of findings obtained following the use of doxorubicin (Adriamycin [A]; Adria Laboratories, Columbus, OH) for the postoperative treatment of patients with primary breast cancer and positive axillary nodes, no clear consensus exists regarding its worth when used in that setting. In June 1981, the National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented two randomized clinical trials aimed at evaluating the worth of doxorubicin when administered in conjunction with melphalan (L-PAM) and fluorouracil (5-FU) (PF). A prior NSABP study identified cohorts of patients who did or did not benefit from tamoxifen (TAM, T) when used with chemotherapy. That information was employed in the design of the present studies. Women considered responsive to TAM (1,106) were randomized between PFT and PAFT, and those nonresponsive to TAM (707) were randomized between PF and PAF. Findings through 6 years of follow-up (mean duration of potential time on study, 64 months and 63 months, respectively) indicate that non-TAM-responsive patients who received PAF had a significantly better disease-free survival (DFS) (P = .003) and survival (P = .05) than did those receiving PF. By contrast, there was no significant difference in DFS (P = .6) or survival (P = .7) between PFT- and PAFT-treated patients. No disparity in the amount of drug received, whether related to the median amount or to dose-intensity, is present to account for the difference in findings between the studies. Aside from alopecia and emesis, the toxicity from the doxorubicin-containing regimens was similar to those in which doxorubicin was omitted. Cardiomyopathy was not a significant finding; there were no deaths from cardiac toxicity. The incidence of arterial and venous complications in patients receiving TAM was less than reported by others.