%0 Journal Article
%T Response to anti-HER2 neoadjuvant chemotherapy in HER2-positive invasive breast cancers with different HER2 FISH patterns.
%A Lv H
%A Bai QM
%A Li M
%A Cai MY
%A Zhou SL
%A Liu Y
%A Wang ZH
%A Shui RH
%A Lu HF
%A Xu XL
%A Yu BH
%A Tu XY
%A Bi R
%A Cheng YF
%A Zhou XY
%A Shao ZM
%A Yang WT
%J J Clin Pathol
%V 0
%N 0
%D 2024 Feb 12
%M 38346865
%F 4.463
%R 10.1136/jcp-2023-209069
%X <B>OBJECTIVE: </B>Human epidermal growth factor receptor 2 (HER2)-positive patients with breast cancer may have different HER2/CEP17 ratios and HER2 copy numbers, with inconsistent responses to anti-HER2 neoadjuvant chemotherapy (NACT). Our study aimed to explore the relationship between different HER2 fluorescence in situ hybridisation (FISH) patterns in HER2-positive patients with breast cancer and responses to anti-HER2 NACT.<BR><B>METHODS: </B>527 patients with HER2-positive invasive breast cancer who received anti-HER2 NACT from 2015 to 2022 were included and divided into three groups by FISH results, namely group A: HER2/CEP17<2.0 and HER2 copy numbers ≥6.0, HER2 immunohistochemistry 2/3+; group B: HER2/CEP17≥2.0 and HER2 copy numbers ≥4.0 and <6.0; group C: HER2/CEP17≥2.0 and HER2 copy numbers ≥6.0. We compared clinicopathological characteristics and pathological complete response (pCR) rates of different groups.<BR><B>RESULTS: </B>According to HER2 FISH results, 12 patients (2.3%, 12/527) were in group A, 40 (7.6%, 40/527) were in group B and 475 (90.1%, 475/527) were in group C. The pCR rate was the lowest in group B (5.0%), while the pCR rates in group A and group C were 33.3% and 44.4%, respectively (p (group A vs. B) =0.021, p (group C vs. B) < 0.001). Both univariate and multivariate analyses revealed that HER2 FISH pattern was correlated with pCR rate (p (group C vs. B) < 0.001, p (group C vs. B) = 0.025).<BR><B>CONCLUSIONS: </B>Patients with HER2/CEP17≥2.0 and HER2 copy numbers ≥4.0 and <6.0 do not benefit to the same extent from current anti-HER2 therapies as FISH-positive patients with other patterns.