A comparison study of HER2 protein overexpression and its gene status in breast cancer
- Author:
Suria Hayati Md Pauzi
1
Author Information
1. Department of Pathology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, 56000, Kuala Lumpur, Malaysia
- Collective Name:Suria Hayati Md Pauzi; Hanis Nabihah Saari; Muhammad Ridzuan Roslan; Sharifah Nor Shairah Syed Khair Azman Jamalulil; Irene Scully Tauan; Fatin Adiela Mohd Rusli; Azimatun Noor Aizuddin
- Publication Type:Journal Article
- Keywords:
breast cancer;
HER2 gene;
HER2 immunohistochemistry;
DDISH
- MeSH:
breast cancer
- From:The Malaysian Journal of Pathology
2019;41(2):133-138
- CountryMalaysia
- Language:English
-
Abstract:
Introduction: Evaluation of HER2 status in breast cancer using immunohistochemistry (IHC) and in-situ-hybridisation (ISH) study is important to establish prognosis and to select patient for targeted therapy. Objective: The study aims to determine the concordance between HER2 protein IHC score and its gene status by dual-colour dual-hapten in-situ-hybridization (DDISH) study. Materials and Methods: Retrospective study was performed on 767 referred breast cancer cases over a period of five years. The HER2 IHC score (the initial and repeat test score) and the results of HER2 gene status by DDISH were retrieved from the histopathological reports. The agreement between initial IHC score with repeat test score was measured using Cohen Kappa. Chi square test analyzed the association between HER2 IHC score with its gene status by DDISH. Results: The concordance of HER2 IHC score between the initial and repeat test were 52.7% and 89.4% for IHC score 2+ and 3+ respectively. There was moderate agreement of HER2 IHC score between the initial and repeat test score (κ = 0.526, p<0.001). A significant association noted between HER2 IHC score with its gene status by DDISH (p<0.001). Only 56 out of 207 cases (27.1%) with 2+ IHC score showed HER2 gene amplification while the majority of cases with 3+ IHC score were gene-amplified (446 out of 451, 98.9%). Conclusion: ISH study should be done in all IHC-equivocal cases (2+) to select patient for targeted therapy. Gene amplification must also be confirmed in IHC-positive cases (3+) to prevent from giving non-effective treatment with possible adverse effects to patient with nonamplified HER2 gene.
- Full text:5.2019my1003.pdf
