Pathological response to preoperative concurrent chemo-radiotherapy for breast cancer: results of a phase II study

This study evaluated, in terms of pathological complete response (pCR) and acute toxicity, preoperative concurrent (5-fluorouracil (5-FU)-vinorelbine) chemoradiotherapy for large breast cancers. A total of 60 women were included in the study. Chemotherapy consisted of 4 cycles of 5-FU, 500 mg/m2/d, continuous infusion (d1-d5) and vinorelbine, 25 mg/m2 (d1; d6). Starting with the second cycle, radiotherapy delivered 50 Gy to the breast and 46 Gy to the internal mammary and supra/infra-clavicular lymph nodes. Breast surgery and axillary lymph node dissection were then performed. Four patients did not complete their chemotherapy. Breast conservation was possible in 69% of patients. The rate of pCR was 27%. Three factors were associated with pCR: histological grade 3, absence of hormonal receptors and high mitotic index. Grade 4 haematological toxicity occurred in 22% of patients. In conclusion, chemoradiotherapy demonstrated good efficacy, both in terms of pCR and in allowing breast conservation with acceptable tolerance.