RT Journal Article T1 Different Pathological Complete Response Rates According to PAM50 Subtype in HER2+ Breast Cancer Patients Treated With Neoadjuvant Pertuzumab/Trastuzumab vs. Trastuzumab Plus Standard Chemotherapy: An Analysis of Real-World Data. A1 Díaz-Redondo, Tamara A1 Lavado Valenzuela, Rocío A1 Jiménez-Rodríguez, Begoña A1 Pascual, Tomás A1 Gálvez, Fernando A1 Falcón, Alejandro A1 Álamo, María del Carmen A1 Morales-Estévez, Cristina A1 Amerigo, Marta A1 Pascual, Javier A1 Sánchez-Muñoz, Alfonso A1 González-Guerrero, Macarena A1 Vicioso-Recio, Luis Prudencio A1 Laborda-Illanes, Aurora A1 Ortega-Jiménez, María Victoria A1 Pérez-Villa, Lidia A1 Fernández-Martínez, Aranzazu A1 Chic, Nuria A1 Jerez-Aragonés, José Manuel A1 Álvarez-Pérez, Martína A1 Prat, Aleix A1 Ribelles, Nuria A1 Alba-Conejo, Emilio K1 Mamas - Cáncer - Tratamiento K1 Farmacología clínica AB Double blockade with pertuzumab and trastuzumab combined with chemotherapy is the standard neoadjuvant treatment for HER2-positive early breast cancer. Data derived from clinical trials indicates that the response rates differ among intrinsic subtypes of breast cancer. The aim of this study is to determine if these results are valid in real-world patients. Methods: A total of 259 patients treated in eight Spanish hospitals were included and divided into two cohorts: Cohort A (132 patients) received trastuzumab plus standard neoadjuvant chemotherapy (NAC), and Cohort B received pertuzumab and trastuzumab plus NAC (122 patients). Pathological complete response (pCR) was defined as the complete disappearance of invasive tumor cells. Assignment of the intrinsic subtype was realized using the research-based PAM50 signature. Results: There were more HER2-enriched tumors in Cohort A (70 vs. 56%) and more basal-like tumors in Cohort B (12 vs. 2%), with similar luminal cases in both cohorts (luminal A 12 vs. 14%; luminal B 14 vs. 18%). The overall pCR rate was 39% in Cohort A and 61% in Cohort B. Better pCR rates with pertuzumab plus trastuzumab than with trastuzumab alone were also observed in all intrinsic subtypes (luminal PAM50 41 vs. 11.4% and HER2-enriched subtype 73.5 vs. 50%) but not in basal-like tumors (53.3 vs. 50%). In multivariate analysis the only significant variables related to pCR in both luminal PAM50 and HER2-enriched subtypes were treatment with pertuzumab plus trastuzumab (Cohort B) and histological grade 3. Conclusions: With data obtained from patients treated in clinical practice, it has been possible to verify that the addition of pertuzumab to trastuzumab and neoadjuvant chemotherapy substantially increases the rate of pCR, especially in the HER2-enriched subtype but also in luminal subtypes, with no apparent benefit in basal-like tumors PB Frontiers Media YR 2019 FD 2019 LK https://hdl.handle.net/10630/31264 UL https://hdl.handle.net/10630/31264 LA eng NO Díaz-Redondo T, Lavado-Valenzuela R, Jimenez B, Pascual T, Gálvez F, Falcón A, Alamo MDC, Morales C, Amerigo M, Pascual J, Sanchez-Muñoz A, González-Guerrero M, Vicioso L, Laborda A, Ortega MV, Perez L, Fernandez-Martinez A, Chic N, Jerez JM, Alvarez M, Prat A, Ribelles N, Alba E. Different Pathological Complete Response Rates According to PAM50 Subtype in HER2+ Breast Cancer Patients Treated With Neoadjuvant Pertuzumab/Trastuzumab vs. Trastuzumab Plus Standard Chemotherapy: An Analysis of Real-World Data. Front Oncol. 2019 Nov 5;9:1178. doi: 10.3389/fonc.2019.01178. PMID: 31750258; PMCID: PMC6848376. NO Este articulo ha sido publicado en la revista Frontiers in Oncology. Esta versión tiene Licencia Creative Commons CC-BY DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 19 ene 2026