| Literature DB >> 31974492 |
Shuling Zhou1,2, Fei Yang1,2, Qianming Bai1,2, Anqi Li1,2, Ming Li1,2, Siyuan Zhong1,2, Hong Lv1,2, Ruohong Shui1,2, Xiaoyu Tu1,2, Rui Bi1,2, Xiaoli Xu1,2, Yufan Cheng1,2, Baohua Yu1,2, Shaoxian Tang1,2, Xiangjie Sun1,2, Xiaoyan Zhou1,2, Wentao Yang3,4.
Abstract
Invasive micropapillary carcinoma is characterized by the inside-out growth of tumor clusters and displays incomplete membrane immunostaining of HER2. According to the 2018 American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP) HER2-testing recommendation, moderate to intense but incomplete staining could be scored as immunohistochemical 2+. Furthermore, the criteria of immunohistochemical 3+ for this staining pattern are not mentioned. One hundred and forty-seven cases of invasive micropapillary carcinoma with moderate-to-intense HER2 immunostaining were enrolled. Invasive micropapillary carcinoma components of all cases were scored as immunohistochemical 2+ based on the 2018 ASCO/CAP recommendation. The invasive micropapillary carcinoma component varied from 10% to 100% (mean, 80%). Invasive micropapillary carcinoma components of all 147 tumors exhibited reversed polarity and incomplete basolateral HER2 membrane staining. One hundred and seventeen of the tumors (80%, 117/147) had moderate staining, and 38 (32%, 38/117) showed HER2 gene amplification by fluorescence in-situ hybridization. HER2 gene was amplified in all the remaining 30 tumors (20%, 30/147) that exhibited intense basolateral membrane staining. Besides, average HER2 signals per cell and ratio of HER2/CEP17 were significantly higher in the intense-staining tumors compared with the moderate-staining tumors (p < 0.0001). Follow-up data were available for 140 patients. None of the patients were died. The follow-up time ranged from 1 month to 99 months (median, 57 months). Thirteen (9%, 13/140) patients exhibited disease progression (recurrence or metastasis). HER2 gene amplification was correlated inversely with estrogen receptor (p = 0.000) and progesterone receptor (p = 0.000) expression, and positively with histological grade (p = 0.003) and disease progression (p = 0.000). Invasive micropapillary carcinoma with intense clear linear basolateral membrane immunostaining indicates HER2 positivity, even if the staining is incomplete. They should be classified as immunohistochemical 3+ rather than immunohistochemical 2+, which would avoid further fluorescence in-situ hybridization-testing procedure and greatly save the related time, labor, and financial costs. Ultimately, ensure all patients with HER2 gene amplification obtain effective targeted therapy in time.Entities:
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Year: 2020 PMID： 31974492 DOI： 10.1038/s41379-020-0461-z
Source DB: PubMed Journal: Mod Pathol ISSN： 0893-3952 Impact factor: 7.842