HER2 mRNA expression in breast cancers with equivocal immunohistochemical results using in situ mRNA hybridization
- VernacularTitle:HER2免疫组织化学结果不确定的乳腺癌原位 mRNA 表达特征
- Author:
Shafei WU
1
;
Yuanyuan LIU
;
Ying JIANG
;
Yufeng LUO
;
Quancai CUI
;
Zhiyong LIANG
;
Xuan ZENG
Author Information
1. 100730,中国医学科学院 北京协和医学院 北京协和医院病理科
- Keywords:
Breast Cancer;
Genes,erbB-2;
Immunohistochemistry;
In situ hybridization
- From:
Chinese Journal of Pathology
2015;(10):725-728
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate in situ mRNA expression of HER 2 oncogene in breast cancers with equivocal immunohistochemical results , and to explore the potential feasibility of RNAscope technique in evaluating HER2 status in breast cancers .Methods Sixty-nine FFPE samples of invasive ductal breast cancer with equivocal HER 2 immunohistochemistry results ( IHC 2+) were collected from surgical excisions from Peking Union Medical College Hospital between June 2010 and June 2013.HER2 status and in situ mRNA expression were tested by fluorescence in situ hybridization ( FISH) and RNAscope respectively using tissue microarray constructed from tumor paraffin blocks .The results of HER2 mRNA expression were scored 0 to 4 ( from low to high levels ) according to mRNA expression in 100 cancer cells .HER2 mRNA expression was evaluated in two groups of patients , with positive and negative FISH results .Results Twenty-three of the 69 samples were FISH positive, including 16 samples that were scored 4 by RNAscope (70%,16/23), 6 samples were scored 3 ( 26%,6/23 ) and one sample was scored 2 ( 4%,1/23 ) .High in situ mRNA expression (score 4 or 3) were observed in 96%of HER2 FISH positive samples.All of samples that were scored 4 by RNAscope were FISH positive .Forty-six samples were FISH negative , including 17 samples that were scored 3 by RNAscope (37%,17/46), 25 samples were scored 2 (54%,25/46), and 4 samples were scored 1 (9%,4/46).Conclusions Breast cancer with HER2 IHC 2 +could be further classified according to in situ mRNA expression status .Among them, RNAscope score of 4 could be one of the interpretation criteria for re-testing IHC 2+samples.In situ detection of HER2 mRNA may be an additional candidate method of confirmation for HER 2 gene amplification or protein overexpression , and has potential clinical utility.
