Triple negative breast cancer subtypes and pathologic complete response rate to neoadjuvant chemotherapy

• DOI: 10.18632/oncotarget.25413
• Publication Date: 2018-05-29T13:49:26Z
• Authors: Angela Santonja; Alfonso Sánchez-M...; Ana Lluch; Maria Rosario Chi...; Joan Albanell; José Ignacio Chacón; Silvia Antolín; José Manuel Jerez; Juan de la Haba; Vanessa de Luque; Cristina Elisabet...; Luis Vicioso; Yéssica Plata; César Luis Ramíre...; Martina Álvarez; Casilda Llácer; Irene Zarcos-Pedr...; Eva Carrasco; Rosalía Caballero; Miguel Martín; Emilio Alba
• Keywords: Carcinogénesis; subtyping; 610; Neoadjuvant chemotherapy; Carboplatin; 3. Good health; Subtyping; pathologic complete response; 03 medical and health sciences; Breast cancer; 0302 clinical medicine; triple negative breast cancer; Neoadjuvant therapy; carboplatin; Pathologic complete response; Triple negative breast cancer; neoadjuvant therapy; Quimioterapia; Triple negative; Cáncer - Tratamiento; Research Paper

Triple negative breast cancer (TNBC) is a heterogeneous disease with distinct molecular subtypes that differentially respond to chemotherapy and targeted agents. The purpose of this study is to explore the clinical relevance of Lehmann TNBC subtypes by identifying any differences in response to neoadjuvant chemotherapy among them. We determined Lehmann subtypes by gene expression profiling in paraffined pre-treatment tumor biopsies from 125 TNBC patients treated with neoadjuvant anthracyclines and/or taxanes +/- carboplatin. We explored the clinicopathological characteristics of Lehmann subtypes and their association with the pathologic complete response (pCR) to different treatments. The global pCR rate was 37%, and it was unevenly distributed within Lehmann's subtypes. Basal-like 1 (BL1) tumors exhibited the highest pCR to carboplatin containing regimens (80% vs 23%, p=0.027) and were the most proliferative (Ki-67>50% of 88.2% vs. 63.7%, p=0.02). Luminal-androgen receptor (LAR) patients achieved the lowest pCR to all treatments (14.3% vs 42.7%, p=0.045 when excluding mesenchymal stem-like (MSL) samples) and were the group with the lowest proliferation (Ki-67≤50% of 71% vs 27%, p=0.002). In our cohort, only tumors with LAR phenotype presented non-basal-like intrinsic subtypes (HER2-enriched and luminal A). TNBC patients present tumors with a high genetic diversity ranging from highly proliferative tumors, likely responsive to platinum-based therapies, to a subset of chemoresistant tumors with low proliferation and luminal characteristics.