ORIGINAL RESEARCH article
Front. Oncol.
Sec. Breast Cancer
Patterns of Response of Breast Cancer After Neoadjuvant Chemotherapy According to Molecular Subtype
Provisionally accepted
Malak Ghezzawi
Mohammad Hadi El Charif
Lynn LteifVahe PanossianAnthony HaddadSali SarkisYara ZebianMira KheilMohammad Ali MaktabiNajla FakhruddinJaber Abass
Hazem AssiZiad Salem
Eman Sbaity*- American University of Beirut, Beirut, Lebanon
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Word count: 227 Background: Neoadjuvant chemotherapy (NACT) is a key component in the treatment of locally advanced breast cancer, with pathologic complete response (pCR) varying by molecular subtype. This study evaluates pCR rates following NACT in a Lebanese cohort, stratified by molecular and clinicopathological features.Methods: This retrospective cohort included 187 women with stage T1-T4, N1, M0 breast cancer treated at the American University of Beirut Medical Center between 2010 and 2016.Molecular subtypes (Luminal A, Luminal B, HER2-positive, triple-negative) were determined by immunohistochemistry and/or FISH. pCR was defined as ypT0N0. Univariate and multivariate analyses were performed to identify predictors of pCR.Results: The median age was 45 years. Molecular subtype distribution was: Luminal A (28.9%), Luminal B (45.5%), HER2-positive (11.8%), and triple-negative (13.9%). Overall pCR was achieved in 12.8% (24/187) of patients. pCR rates significantly differed across molecular subtypes: HER2 -enriched 45.5%, Luminal B 11.8%, triple-negative 11.5%, and Luminal A 1.9% (p = 0.005). Axillary involvem ent was also significantly associated with pCR (p < 0.001), while clinical T stage, tumor grade, focality/centricity, and chem otherapy regim en showed no signific ant associations. In multivariable logistic regression, molecular subtype rem ained an independent predictor of pCR (p = 0.002).Conclusion: pCR rates varied markedly among molecular subtypes, being highest in HER2-enriched tumors and lowest in Luminal A. These findings support molecular subtype as a key determinant of treatment response and highlight its role in guiding neoadjuvant treatment strategies.
Keywords: breast cancer, Neoadjuvant chemotheraphy, Pathological complete response, Molecular subtype, residual disease
Received: 21 Jul 2025; Accepted: 13 Nov 2025.
Copyright: © 2025 Ghezzawi, El Charif, Lteif, Panossian, Haddad, Sarkis, Zebian, Kheil, Maktabi, Fakhruddin, Abass, Assi, Salem and Sbaity. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Eman Sbaity, es25@aub.edu.lb
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