Characterisation of complete responders to combination chemotherapy for advanced breast cancer: a retrospective EORTC Breast Group study.

This retrospective study was undertaken to characterise the natural history of women achieving complete response (CR) following standard dose combination chemotherapy for metastatic breast cancer (MBC), and to analyse the significance of various patient, disease and treatment characteristics in determining survival and time to disease progression. 75 patients achieving a CR following standard dose combination chemotherapy or combined chemoendocrine therapy for MBC have been studied. At a median follow-up of 6 years, 28% of patients are still alive, with 18 of 21 patients showing no evidence of disease. 15 (20%) patients, with median follow-up of 61 months from start of chemotherapy, have never experienced relapse. Median overall survival is 32.5 months. Multivariate analysis for survival identified inclusion of anthracyclines and WHO performance status as significant predictors of good long-term outcome. Concomitant hormonotherapy almost reached statistical significance in our multivariate analysis. Neither dominant site of disease nor disease-free interval were significant determinants of complete remission. With conventional dose combination chemotherapy, approximately 20% of women with MBC who have achieved a clinical CR have been shown to be expected to remain alive and free of disease at 5 years. Inclusion of an anthracycline appears to be an important determinant of durability of CR and patient survival.