Deciphering HER2-low breast cancer (BC) : insights from real-world data in early stage breast cancer
Pous, Anna (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Bernat-Peguera, Adrià (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
López-Paradís, Assumpció (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Cirauqui, Beatriz (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Quiroga García, Vanesa (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Teruel, Iris (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Felip, Eudald (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Ferrando Díez, Angelica (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Bergamino, Milana (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Boronat, Laia (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Romeo, Margarita (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Soler, Gemma (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Mariño, Christian (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Rodríguez-Martínez, Paula (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Pons, Laura (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Ballana, Ester (Institut Germans Trias i Pujol. Institut de Recerca de la Sida IrsiCaixa)
Martínez Cardús, Anna (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)
Margelí, Mireia (Institut Germans Trias i Pujol. Hospital Universitari Germans Trias i Pujol)

Date:	2024
Abstract:	Background: Human epidermal growth factor receptor 2 (HER2)-low has emerged as a potential new entity in breast cancer (BC). Data on this subset are limited, and prognostic results are controversial, evidencing the need of further data in a BC real-world cohort. Methods: Patients with HER2-negative stage I-III BC diagnosed between 2006 and 2016 were retrospectively reviewed in a single cohort from the Catalan Institute of Oncology Badalona. Demographics and clinicopathological characteristics were examined via medical charts/electronic health records. We aim to describe and compare HER2-0/HER2-low populations through Chi-square or Fisher test, and explore its prognostic impact using Kaplan-Meier curves and Cox regression models. Results: From a cohort of 1755 BC patients, 1401 invasive HER2-negative, stage I-III cases were evaluated. 87% were hormone receptor (HR)-positive versus 13% triple negative (TNBC). Overall, 43% were HER2-0 and 57% HER2-low (61% immunohistochemistry (IHC) 1+ and 39% IHC 2+). Comparing HER2-low versus HER2-0, HER2-low showed higher proportion of estrogen receptor (ER)-positive (91. 6% vs 79. 9%, p ⩽ 0. 001) and progesterone receptor (PR)-positive (79. 8% vs 68. 9%, p ⩽ 0. 001) cases. HER2-0 exhibited higher proportion of TNBC (20. 1% vs 8. 4%, p = 0. 001), grade III tumors (28. 8% vs 23. 5%, p = 0. 039), and higher Ki67 median value (26. 47% vs 23. 88%, p = 0. 041). HER2-low was associated with longer time to distant recurrence (TTDR) compared to HER2-0 (67. 8 vs 54. 1 months; p = 0. 015) and better BC-related survival (19. 2 vs 16. 3 years; p = 0. 033). In the multivariable analysis, HER2-low was not an independent prognostic factor for TTDR and BC-related survival. ER expression showed a strong association with longer TTDR (Hazard Ratio: 0. 425, p ⩽ 0. 001) and improved BC-related survival (Hazard Ratio: 0. 380, p ⩽ 0. 001). PR expression was also associated with longer TTDR (Hazard Ratio: 0. 496, p ⩽ 0. 001), and improved BC-related survival (Hazard Ratio: 0. 488, p ⩽ 0. 001). Histological grade III was significantly associated with shorter TTDR (Hazard Ratio: 1. 737, p = 0. 002). Positive nodal status was the strongest factor correlated with worse BC-related survival (Hazard Ratio: 2. 747, p ⩽ 0. 001). Conclusion: HER2-low was significantly associated with HR-positive disease, whereas HER2-0 group had higher incidence of TNBC, histological grade III and higher Ki67%. Although HER2-low group was associated with longer TTDR and improved BC-related survival, these findings could be explained by the greater proportion of favorable prognostic features in this subgroup compared to HER2-0.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Biomarkers ; Breast cancer ; HER2-low ; Human epidermal growth factor receptor 2 ; Survival
Published in:	Therapeutic Advances in Medical Oncology, Vol. 16 (October 2024) , ISSN 1758-8359

DOI: 10.1177/17588359241290720
PMID: 39449733

15 p, 1.6 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut d'Investigació en Ciencies de la Salut Germans Trias i Pujol (IGTP)
Articles > Research articles
Articles > Published articles