Dose-dense adjuvant chemotherapy in early breast cancer patients: 15-year results of the Phase 3 Mammella InterGruppo (MIG)-1 study
Eva Blondeaux, Matteo Lambertini, Andrea Michelotti, Benedetta Conte, Marco Benasso, Chiara Dellepiane, Claudia Bighin, Simona Pastorino, Alessia Levaggi, Alessia D’ Alonzo, Francesca Poggio, Giulia Buzzatti, Chiara Molinelli, Piero Fregatti, Sergio Bertoglio, Francesco Boccardo, Lucia Del Mastro
Abstract
BACKGROUND: Adjuvant chemotherapy is the standard of care in high-risk early breast cancer patients. Dose-dense should be the preferred schedule of administration. However, its long-term benefit is unknown. METHODS: In the Italian multicentre Phase 3 randomised MIG-1 trial, node-positive and high-risk node- negative breast cancer patients were randomised to receive six cycles of adjuvant fluorouracil, epirubicin and cyclophosphamide regimen administered every 3 (FEC21) or 2 (FEC14) weeks. The primary endpoint was overall survival (OS), and the secondary endpoint was event-free survival (EFS). RESULTS: From 1992 to 1997, 1214 patients were included. Median follow-up was 15.8 years. In all, 15-year OS was 71% and 68% in the FEC14 and FEC21 groups, respectively (HR = 0.89; p = 0.25). In all, 15-year EFS was 47% and 43% in the FEC14 and FEC21 groups, respectively (HR = 0.87; p = 0.18). In a pre-planned subgroup analysis, among patients with hormone receptor-negative tumours, 15-year OS was 70% and 65% in the FEC14 and FEC21 groups, respectively (HR = 0.73; 95% CI: 0.51-1.06); 15-year EFS was 58% and 43% in the FEC14 and FEC21 groups, respectively (HR = 0.70; 95% CI: 0.51-0.96). CONCLUSIONS: Updated results from the MIG-1 study are numerically in favour of dose-dense chemotherapy, and suggest a long-term benefit of this approach in high-risk early breast cancer patients.