PMID- 31213407
OWN - NLM
STAT- MEDLINE
DCOM- 20200811
LR  - 20200811
IS  - 1938-0666 (Electronic)
IS  - 1526-8209 (Linking)
VI  - 19
IP  - 5
DP  - 2019 Oct
TI  - The Impact of Partial Weak Staining in Normal Breast Epithelium on the 
      Reliability of Immunohistochemistry Results in HercepTest-positive Breast Cancer.
PG  - 340-344
LID - S1526-8209(18)30847-4 [pii]
LID - 10.1016/j.clbc.2019.04.017 [doi]
AB  - INTRODUCTION: Although normal epithelial cells do not show human epidermal growth 
      factor receptor-2 (HER2) gene amplification and should lack membrane staining by 
      HER2 immunohistochemistry (IHC), HER2 staining in benign breast epithelium is 
      occasionally encountered. The significance of this occurrence has not yet been 
      adequately studied, and its associated American Society of Clinical 
      Oncology/College of American Pathologists recommendations are vague. Our 
      objective is to assess the correlation between HER2 IHC 3+ breast cancer cases 
      with normal epithelium staining (NES) and their corresponding fluorescence in 
      situ hybridization (FISH) results, and to suggest recommendations for 
      interpretation. MATERIALS AND METHODS: A total of 154 breast cancer cases with 
      HER2 IHC 3+ were reviewed. NES, along with other clinicopathologic 
      characteristics, were recorded. NES was scored as present or absent. All study 
      cases were sent for FISH testing. All cases, and particularly those that showed 
      false positivity for IHC (positive IHC, negative FISH) were examined for NES. 
      RESULTS: Of the 154 cases, 146 cases were FISH-positive (94.8%) and 2 failed FISH 
      testing (1.3%). Conversely, 22% (34/154) of the cases showed NES for HER2. Of 
      these 34 cases, 23 (67%) were FISH-amplified, 9 (26%) were FISH not amplified, 
      and 2 failed FISH testing. Notably, all of the false-positive (FISH-negative) 
      breast cancer cases showed some degree of positivity in normal breast epithelium. 
      CONCLUSIONS: Our findings, though descriptive, show a very strong association 
      between NES and false-positive HER2 IHC. This confirms the need to carefully 
      evaluate IHC-positive breast cancers for NES, and to have a low threshold for 
      confirmatory testing by FISH.
CI  - Copyright (c) 2019 Elsevier Inc. All rights reserved.
FAU - Farra, Chantal
AU  - Farra C
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon.
FAU - Fedda, Faysal
AU  - Fedda F
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon.
FAU - Tfayli, Arafat
AU  - Tfayli A
AD  - Department of Internal Medicine, American University of Beirut Medical Center, 
      Beirut, Lebanon.
FAU - Tawil, Ayman
AU  - Tawil A
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon.
FAU - Zaatari, Ghazi
AU  - Zaatari G
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon.
FAU - Ashkar, Hanin
AU  - Ashkar H
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon.
FAU - Issa, Grece
AU  - Issa G
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon.
FAU - Boulos, Fouad
AU  - Boulos F
AD  - Department of Pathology and Laboratory Medicine, American University of Beirut 
      Medical Center, Beirut, Lebanon. Electronic address: fb17@aub.edu.lb.
LA  - eng
PT  - Journal Article
DEP - 20190518
PL  - United States
TA  - Clin Breast Cancer
JT  - Clinical breast cancer
JID - 100898731
RN  - 0 (Biomarkers, Tumor)
RN  - EC 2.7.10.1 (ERBB2 protein, human)
RN  - EC 2.7.10.1 (Receptor, ErbB-2)
SB  - IM
CIN - Clin Breast Cancer. 2020 Feb;20(1):87-88. PMID: 31732190
MH  - Biomarkers, Tumor/*analysis
MH  - Breast/metabolism/*pathology
MH  - Breast Neoplasms/genetics/metabolism/*pathology
MH  - Female
MH  - Follow-Up Studies
MH  - Gene Amplification
MH  - Humans
MH  - Immunohistochemistry/*methods
MH  - In Situ Hybridization, Fluorescence/*methods
MH  - Middle Aged
MH  - Prognosis
MH  - Receptor, ErbB-2/*genetics/*metabolism
OTO - NOTNLM
OT  - ASCO/CAP recommendations
OT  - False positive HER2
OT  - Fluorescent in-situ hybridization
OT  - HER2 gene amplification
OT  - Normal breast epithelium
EDAT- 2019/06/20 06:00
MHDA- 2020/08/12 06:00
CRDT- 2019/06/20 06:00
PHST- 2018/12/10 00:00 [received]
PHST- 2019/04/24 00:00 [revised]
PHST- 2019/04/28 00:00 [accepted]
PHST- 2019/06/20 06:00 [pubmed]
PHST- 2020/08/12 06:00 [medline]
PHST- 2019/06/20 06:00 [entrez]
AID - S1526-8209(18)30847-4 [pii]
AID - 10.1016/j.clbc.2019.04.017 [doi]
PST - ppublish
SO  - Clin Breast Cancer. 2019 Oct;19(5):340-344. doi: 10.1016/j.clbc.2019.04.017. Epub 
      2019 May 18.