TY - JOUR
T1 - HER2 testing in breast cancers
T2 - comparison of assays and interpretation using ASCO/CAP 2013 and 2018 guidelines
AU - McLemore, Lauren E.
AU - Albarracin, Constance T.
AU - Gruschkus, Stephen K.
AU - Bassett, Roland L.
AU - Wu, Yun
AU - Dhamne, Sagar
AU - Yim, Isaiah
AU - Lin, Kevin
AU - Bedrosian, Isabelle
AU - Sneige, Nour
AU - Chen, Hui
N1 - Funding Information:
This work was supported in part by the NIH/NCI Cancer Center Support Grant (P30 CA016672) used for the Biostatistics Resource Group.
Funding Information:
We would like to thank Dawn Chalaire from the Department of Scientific Publications, at The University of Texas MD Anderson Cancer Center for her assistance in editing this document and Kim-Anh Vu from the Department of Pathology for her help with graphic images.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2021/5
Y1 - 2021/5
N2 - Purpose: HER2 overexpression and gene amplification are routinely tested by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. In addition, HER2 mRNA expression is also tested by the Oncotype DX assay. Discordance between laboratories among the different assays remains a problem. To improve the routine HER2 reporting, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) updated their guidelines in 2018. Our study will compare concordance of HER2 status by IHC and FISH using ASCO/CAP 2013 and 2018 guidelines with Oncotype DX. Methods: We retrospectively reviewed 657 estrogen receptor positive primary breast cancer cases with available Oncotype DX tests between 2011 and 2018. Medical records were reviewed for HER2 results by IHC, FISH, and Oncotype DX. The HER2 results by different assays and between 2013 and 2018 guidelines were compared. Results: Of the 657 cases, 280 were tested by IHC, FISH, and Oncotype DX. HER2-equivocal cases by IHC 2013 guidelines were all negative (67/67, 100%) by FISH 2018 guidelines and by Oncotype DX. HER2-equivocal cases by FISH 2013 guidelines were all negative (16/16, 100%) by FISH 2018 guidelines, while 15/16 (93.8%) negative and 1/16 (6.2%) equivocal by Oncotype DX. The HER2-equivocal and HER2-negative groups were similar in age, gender, histology, grade, and Ki67 score. Conclusions: HER2 concordance was highest between Oncotype DX (99.6%) and FISH per 2018 guidelines. This suggests that the ASCO/CAP 2018 guidelines improved the accurate stratification of HER2-equivocal cases.
AB - Purpose: HER2 overexpression and gene amplification are routinely tested by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. In addition, HER2 mRNA expression is also tested by the Oncotype DX assay. Discordance between laboratories among the different assays remains a problem. To improve the routine HER2 reporting, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) updated their guidelines in 2018. Our study will compare concordance of HER2 status by IHC and FISH using ASCO/CAP 2013 and 2018 guidelines with Oncotype DX. Methods: We retrospectively reviewed 657 estrogen receptor positive primary breast cancer cases with available Oncotype DX tests between 2011 and 2018. Medical records were reviewed for HER2 results by IHC, FISH, and Oncotype DX. The HER2 results by different assays and between 2013 and 2018 guidelines were compared. Results: Of the 657 cases, 280 were tested by IHC, FISH, and Oncotype DX. HER2-equivocal cases by IHC 2013 guidelines were all negative (67/67, 100%) by FISH 2018 guidelines and by Oncotype DX. HER2-equivocal cases by FISH 2013 guidelines were all negative (16/16, 100%) by FISH 2018 guidelines, while 15/16 (93.8%) negative and 1/16 (6.2%) equivocal by Oncotype DX. The HER2-equivocal and HER2-negative groups were similar in age, gender, histology, grade, and Ki67 score. Conclusions: HER2 concordance was highest between Oncotype DX (99.6%) and FISH per 2018 guidelines. This suggests that the ASCO/CAP 2018 guidelines improved the accurate stratification of HER2-equivocal cases.
KW - ASCO/CAP guidelines
KW - Breast cancer
KW - FISH
KW - HER2 amplification
KW - HER2 overexpression
KW - Oncotype DX
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U2 - 10.1007/s10549-021-06208-5
DO - 10.1007/s10549-021-06208-5
M3 - Article
C2 - 33813685
AN - SCOPUS:85103636238
SN - 0167-6806
VL - 187
SP - 95
EP - 104
JO - Breast Cancer Research and Treatment
JF - Breast Cancer Research and Treatment
IS - 1
ER -