Los subtipos moleculares en cáncer de mama avanzado responden diferente a la quimioterapia neoadyuvante: evaluación de la respuesta patológica completa y pronóstico

Abstract

Objetive: To examine the pathological complete response (pCR) in the molecular subtypes in patients with locally advanced breast cancer after receiving neoadjuvant chemotherapy (NC) with epirubicin and sequential docetaxel (E-D) and examining their prognostic relevance. Patients and methods: Retrospective longitudinal study of 126 patients with stage III breast cancer. The five molecular subtypes were identified by immunohistochemistry biomarkers. After NC, surgery was performed, and radiotherapy was administered. Results: There are differences in response to NC, pCR rate was superior in the patients in tumors with HER2 overexpression: HER2+ (41.7%) and luminal B/HER2 (LB/HER2: 38.5%). Luminal A (LA) and triple negative (TN) subtypes had a similar pCR (29%). The pCR does not appear to be a marker of overall survival (OS) in LB/ HER2- and LB/HER2+ tumors. The LA and TN population had a better 5-year rate in OS (100% both); it was not observed a significant advantage among these tumors (p = 0.148). The patients with residual tumor had the worst prognosis in terms of OS, especially the LB/HER2- y B/HER2+ (50% both) and HER2 (25%) tumors. Conclusions: The study confirms that pCR was the favorable prognostic factor in OS in three molecular subtypes. There are differences in the pCR between the ER-positive group versus the ER-negative group, suggesting that the molecular mechanisms of susceptibility to NC vary between these two groups.