HER2-low status and response to neoadjuvant chemotherapy in HER2 negative early breast cancer.

Autor: de Moura Leite L; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil. Luciana.leite@accamargo.org.br., Cesca MG; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Tavares MC; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Santana DM; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Saldanha EF; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Guimarães PT; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Sá DDS; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Simões MFE; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Viana RL; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Rocha FG; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Loose SK; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Silva SF; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Pirolli R; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Fogassa CAZ; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Mattos BRS; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Campos FAB; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Sanches SM; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., de Lima VCC; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil., Pondé NF; Department of Medical Oncology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil.
Jazyk: angličtina
Zdroj: Breast cancer research and treatment [Breast Cancer Res Treat] 2021 Nov; Vol. 190 (1), pp. 155-163. Date of Electronic Publication: 2021 Aug 18.
DOI: 10.1007/s10549-021-06365-7
Abstrakt: Purpose: Knowledge on whether low expressions of HER2 have prognostic impact in early-stage breast cancer (BC) and on its response to current chemotherapy protocols can contribute to medical practice and development of new drugs for this subset of patients, changing treatment paradigms. This study aims to evaluate the impact of HER2-low status on response to neoadjuvant chemotherapy (NACT) and survival outcomes in early-stage HER2-negative BC.
Methods: Records from all BC patients treated with NACT from January 2007 to December 2018 in a single cancer center were retrospectively reviewed. HER2-negative (immunohistochemistry [IHC] 0, + 1, or + 2 non-amplified by in situ hybridization [ISH]) patients were included. HER2-low was defined by IHC + 1 or + 2 ISH non-amplified and HER2-0 by IHC 0. The coprimary objectives were to compare pathological complete response (pCR) and relapse-free survival (RFS) between luminal/HER2-low versus luminal/HER2-0 populations and between triple negative (TNBC)/HER2-low versus TNBC/HER2-0.
Results: In total, 855 HER2-negative patients were identified. The median follow-up was 59 months. 542 patients had luminal subtype (63.4%) and 313 had TNBC (36.6%). 285 (33.3%) were HER2-low. Among luminal patients, 145 had HER2 IHC + 1 (26.8%) and 91 had IHC + 2/ISH non-amplified (16.8%). In TNBC, 36 had HER2 IHC + 1 (11.5%) and 13 had IHC + 2/ISH non-amplified (4.2%). Most patients had locally advanced tumors, regardless of subtype or HER2-low status. For luminal disease, pCR was achieved in 13% of HER2-low tumors versus 9.5% of HER2-0 (p = 0.27). Similarly, there was no difference in pCR rates among TNBC: 51% versus 47% in HER2-low versus HER2-0, respectively (p = 0.64). HER2-low was also not prognostic for RFS, with 5-year RFS rates of 72.1% versus 71.7% (p = 0.47) for luminal HER2-low/HER2-0, respectively, and 75.6% versus 70.8% (p = 0.23) for TNBC HER2-low/HER2-0.
Conclusion: Our data does not support HER2-low as a biologically distinct BC subtype, with no prognostic value on survival outcomes and no predictive effect for pCR after conventional NACT.
(© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
Databáze: MEDLINE
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