Adjuvant cyclophosphamide, methotrexate and fluorouracil in node-negative and estrogen receptor-negative breast cancer: Updated results

Abstract

Node-negative breast cancers are considered to comprise a subgroup which is amenable to cure with local-regional therapy alone. However, approximately 30% of affected patients present new disease manifestations within 10 years after surgery. To test the hypothesis that node-negative and estrogen receptor-negative breast cancer patients can benefit from adjuvant chemotherapy, a prospective randomized study was activated at the Istituto Nazionale Tumori of Milan in 1980. The study was conducted in 90 patients operated on for unilateral breast cancer who were then assigned to receive either 12 intravenous cycles of cyclophosphamide, methotrexate and fluorouracil (CMF) every three weeks, or no further treatment. Adjuvant chemotherapy was administered in the outpatient clinic of the Division of Medical Oncology. Patient characteristics were fairly well balanced between the two treatment groups except for primary tumor size: 58% of those with a primary tumor measuring > 2 cm in its largest diameter were randomized in the control group compared with 38% in the CMF regimen (P = 0.06). At 12 years after surgery treatment outcome was significantly superior for patients given adjuvant CMF. The relapse-free survival rate was 71% (95% confidence limits (CL): 56-86) versus 43% (95% CL: 28-58), and total survival was 80% (95% CL: 68-92) versus 50% (95% CL: 34-66), respectively. The benefit from the administration of CMF was evident in all patient subsets and was not influenced by menopausal status. The long-term results of this trial of adjuvant combination chemotherapy confirm our previous observations on the efficacy of adjuvant chemotherapy in node-negative breast cancer patients at high risk of early disease relapse.