Cancers du sein de stade II-IIIA : la radiothérapie exclusive est-elle une option en cas de réponse clinique complète à la chimiothérapie néoadjuvante ?

Abstract

Purpose To determine whether exclusive radiotherapy could be a therapeutic option after complete clinical response (cCR) to neoadjuvant chemotherapy (NCT) for early breast cancers (EBC). Patients and methods Between 1985 and 1999, 1477 patients received néoadjuvante chemotherapy for early breast cancer considered to be too large for primary conservative surgery. Of 165 patients with complete clinical response, 65 were treated by breast surgery (with radiotherapy) and 100 by exclusive radiotherapy. Results The two groups were comparable in terms of baseline characteristics, except for larger initial tumor sizes in the exclusive radiotherapy group. There were no significant differences in overall, disease-free and metastasis-free survivals. Five-year and 10-year overall survivals were 91 and 77% in the no surgery group and 82 and 79% in the surgery group, respectively ( P = 0.9). However, a non-significant trend towards higher locoregional recurrence rates (LRR) was observed in the no surgery group (31 vs. 17% at 10 years; P = 0.06). In patients with complete responses on mammography and/or ultrasound, LRR were not significantly different ( P = 0.45, 10-year LRR: 21 in surgery vs. 26% in exclusive radiotherapy). No significant differences were observed in terms of the rate of cutaneous, cardiac or pulmonary toxicities. Conclusion Surgery is a key component of locoregional treatment for breast cancers that achieved complete clinical response to neoadjuvant chemotherapy.