Combination chemotherapy (CMFVP) versus L-phenylalanine mustard (L-PAM) for operable breast cancer with positive axillary nodes: a Southwest Oncology Group Study.

The Southwest Oncology Group in a prospective randomized study compared one year of adjuvant combination chemotherapy with continuous CMFVP to two years of intermittent L-PAM in women with operable breast cancer with histologically positive axillary lymph nodes. In fully evaluable patients with a 42-month median and 30-month minimum follow-up, treatment failures have occurred in 26% of 145 receiving CMFVP and 47% of 167 women given L-PAM (P = 0.002). Disease-free survival times were significantly longer with CMFVP than with L-PAM in the following subgroups: premenopausal women (P = 0.002), postmenopausal women (P = 0.002), women with 1-3 involved axillary nodes (P = 0.003), and women with four or more involved axillary nodes (P = 0.002). CMFVP was effective in pre- and postmenopausal women. There is a significant difference in survival in favor of CMFVP compared to L-PAM (P = 0.005). The life table estimates of survival at 42 months are 86% for women on the CMFVP treatment arm and 73% for women on the L-PAM treatment arm. There was no correlation between the interval from mastectomy to onset of chemotherapy (between one and six weeks) and recurrence rates. Acute toxicity with both treatment arms was moderate and reversible. These results show that continuous CMFVP is superior to intermittent L-PAM in decreasing recurrences and increasing survival in both pre- and postmenopausal women with operable breast cancer with histologically involved axillary nodes.