Phase III Trial Evaluating the Addition of Paclitaxel to Doxorubicin Followed by Cyclophosphamide, Methotrexate, and Fluorouracil, As Adjuvant or Primary Systemic Therapy: European Cooperative Trial in Operable Breast Cancer

Abstract

PurposeTo evaluate the addition of paclitaxel to an anthracycline-based adjuvant regimen and to compare this combination with the same regimen given as primary systemic (neoadjuvant) therapy.Patients and MethodsA total of 1,355 women with operable breast cancer were randomly assigned to one of three treatments: surgery followed by adjuvant doxorubicin (75 mg/m2) followed by cyclophosphamide, methotrexate, and fluorouracil (CMF; arm A); surgery followed by adjuvant paclitaxel (200 mg/m2) plus doxorubicin (60 mg/m2), followed by CMF (arm B); or paclitaxel (200 mg/m2) plus doxorubicin (60 mg/m2) followed by CMF followed by surgery (arm C). The two coprimary objectives were to assess the effects on relapse-free survival (RFS) of the addition of paclitaxel to postoperative chemotherapy (arm B v arm A) and primary chemotherapy versus adjuvant chemotherapy (arm B v arm C).ResultsDoxorubicin plus paclitaxel followed by CMF was well-tolerated as adjuvant or as primary chemotherapy. The addition of paclitaxel to adjuvant doxorubicin followed by CMF significantly improved RFS compared with adjuvant doxorubicin alone followed by CMF (hazard ratio [HR], 0.73; P = .03). Distant RFS was similarly improved (HR, 0.70; P = .027). There was no significant difference in RFS when the paclitaxel/doxorubicin/CMF chemotherapy was given before surgery compared with the same regimen given after surgery (HR, 1.21; P = .18). However, the rate of breast-conserving surgery was significantly higher with preoperative chemotherapy (63% v 34%; P < .001).ConclusionIncorporating paclitaxel into anthracycline-based adjuvant therapy resulted in a significant improvement in RFS and distant RFS. When given as primary systemic therapy, the paclitaxel-containing regimen allowed breast-sparing surgery in a significant percentage of patients.