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Title: | PAM50 Subtypes in Baseline and Residual Tumors Following Neoadjuvant Trastuzumab-Based Chemotherapy in HER2-Positive Breast Cancer: A Consecutive-Series From a Single Institution |
Author: | Pernas, Sònia Petit, Anna Climent, Fina Paré, Laia Perez Martin, J. Ventura, Luz Bergamino Sirvén, Milana Galván, Patricia Falo, Catalina Morilla, Idoia Fernandez Ortega, Adela Stradella, Stradella Rey, Montse Garcia Tejedor, Amparo Gil Gil, Miguel Prat Aparicio, Aleix |
Keywords: | Càncer de mama Expressió gènica Quimioteràpia Breast cancer Gene expression Chemotherapy |
Issue Date: | 25-Sep-2019 |
Publisher: | Frontiers Media |
Abstract: | Introduction: HER2-enriched subtype has been associated with higher response to neoadjuvant anti-HER2-based therapy across various clinical trials. However, limited data exist in real-world practice and regarding residual disease. Here, we evaluate the association of HER2-enriched with pathological response (pCR) and gene expression changes in pre- and post-treatment paired samples in HER2-positive breast cancer patients treated outside of a clinical trial. Methods: We evaluated clinical-pathological data from a consecutive series of 150 patients with stage II-IIIC HER2-positive breast cancer treated from August 2004 to December 2012 with trastuzumab-based neoadjuvant chemotherapy. Expression of 105 breast cancer-related genes, including the PAM50 genes, was determined in available pre-and post-treatment formalin-fixed paraffin-embedded tumor samples using the nCounter platform. Intrinsic molecular subtypes were determined using the research-based PAM50 predictor. Association of genomic variables with total pCR was performed. Results: The pCR rate was 53.3%, with higher pCR among hormonal receptor (HR)-negative tumors (70 vs. 39%; P < 0.001). A total of 89 baseline and 28 residual tumors were profiled, including pre- and post-treatment paired samples from 26 patients not achieving a pCR. HER2-enriched was the predominant baseline subtype not only in the overall and HR-negative cohorts (64 and 75%, respectively), but also in the HR-positive cohort (55%). HER2-enriched was associated with higher pCR rates compared to non-HER2-enriched subtypes (65 vs. 31%; OR = 4.07, 95% CI 1.65-10.61, P < 0.002) and this association was independent of HR status. In pre- and post-treatment paired samples from patients not achieving a pCR, a lower proportion of HER2-enriched and twice the number of luminal tumors were observed at baseline, and luminal A was the most frequent subtype in residual tumors. Interestingly, most (81.8%) HER2-enriched tumors changed to non-HER2-enriched, whereas most luminal A samples maintained the same subtype in residual tumors. Conclusions: Outside of a clinical trial, PAM50 HER2-enriched subtype predicts pCR beyond HR status following trastuzumab-based chemotherapy in HER2-positive disease. The clinical value of intrinsic molecular subtype in residual disease warrants further investigation. |
Note: | Reproducció del document publicat a: https://doi.org/10.3389/fonc.2019.00707 |
It is part of: | Frontiers In Oncology, 2019, vol. 9, p. 707 |
URI: | http://hdl.handle.net/2445/165152 |
Related resource: | https://doi.org/10.3389/fonc.2019.00707 |
ISSN: | 2234-943X |
Appears in Collections: | Articles publicats en revistes (Ciències Clíniques) Articles publicats en revistes (Institut d'lnvestigació Biomèdica de Bellvitge (IDIBELL)) |
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