[Indication of radiotherapy after neoadjuvant chemotherapy in breast cancer]

Indications for adjuvant radiotherapy in breast cancer are defined from the clinical data and the pathological extent of disease in the surgical specimen. Neoadjuvant chemotherapy could modify the pathological characteristics of the tumour, inducing a pathologic complete response in 15 to 50% of cases, challenging the classical indications of adjuvant radiotherapy. The benefit of adjuvant radiotherapy after neoadjuvant chemotherapy was not prospectively evaluated. Nonetheless, from retrospective series, some recommendations with a low level of proof could be given: (i) after lumpectomy, radiotherapy of the mammary gland must be performed even in case of pathologic complete response; (ii) after mastectomy, postoperative radiotherapy is recommended in case of cT3-T4, cN1-3 (clinical or radiological) or pathologically involved nodes; (iii) irradiation of the lymph nodes areas is more questionable, but could be also proposed in case of cN1 or pN1. These recommendations are in accordance with those recently published by the National Cancer Institute and the French National Cancer Institute.