[Impact of pathological complete response to neoadjuvant chemotherapy in invasive breast cancer according to molecular subtype]

Abstract

Objectives: The aim of this study was to evaluate the impact of pathological complete response (pCR) on overall survival (OS) and recurrence-free survival (RFS) according to molecular subtypes in women treated for an invasive breast cancer after neoadjuvant chemotherapy (NAC).

Methods: All women (n=225) managed with a neoadjuvant chemotherapy for an invasive breast cancer in our institution between January 2007 and December 2013 were included. The characteristics of patients with pCR (pCR-1), breast pCR and axillary pCR were compared to those without pCR (pCR-0) according to the molecular subtypes: luminal A (n=62), luminal B (n=77), Her-2 (n=31) and triple negative (n=55).

Results: NAC concerned 225 patients of whom 36 (16%) had pCR. Achievement of pCR led to significantly better overall survival in women with Her-2 tumors (35% versus 100%, P=0.035) and also to significantly better locoregional survival in women treated for triple negative tumors (P=0.026). Predictive factors of pCR were a high pathologic grade: OR=2.39, IC 95% (1.19-4.83), P=0.008; Her-2 molecular subtype (P=0.008); positive estrogenic hormonal receptors (P=0.006), a positive Her-2 receptor: OR=2.58, IC 95% (1.20-5.54), P=0.01.

Conclusion: Achievement of pCR is an intermediate marker of survival in women managed with NAC for breast cancer.

Keywords: Breast cancer; Cancer du sein; Chimiothérapie néo-adjuvante; Molecular subtypes; Neoadjuvant chemotherapy; Pathological complete response; Réponse histologique complète; Sous-types moléculaires.