TY - JOUR
T1 - Estrogen Receptor-α Quantification in Breast Cancer
T2 - Concordance Between Immunohistochemical Assays and mRNA-In Situ Hybridization for ESR1 Gene
AU - Thomsen, Christian
AU - Nielsen, Søren
AU - Nielsen, Boye S
AU - Pedersen, Sine H
AU - Vyberg, Mogens
PY - 2020/5
Y1 - 2020/5
N2 - Immunohistochemical (IHC) quantification of estrogen receptor-α (ER) is used for assessment of treatment regimen in breast cancer. Different ER IHC assays may produce diverging results, because of different antibody clones, protocols, and stainer platforms. Objective tissue-based techniques to assess sensitivity and specificity of IHC assays are therefore needed. We tested the usability of ER mRNA-in situ hybridization (mRNA-ISH) in comparison with assays based on clones SP1 and 6F11. We selected 56 archival specimens according to their reported ER IHC positivity, representing a wide spectrum from negative to strongly positive cases. The specimens were used to prepare 4 TMAs with 112 cores. Serial sections of each TMA were stained for ER and pan-cytokeratin (PCK) by IHC and ESR1 (ER gene) by mRNA-ISH. Digital image analysis (DIA) was used to determine ER IHC H-score. ESR1 mRNA-ISH was scored both manually and by DIA. DIA showed a nonlinear correlation between IHC and ESR1 mRNA-ISH with R
2 -values of 0.80 and 0.78 for the ER antibody clones SP1 and 6F11, respectively. Comparison of manual mRNA-ISH scoring categories and SP1 and 6F11 IHC H-scores showed a highly significant relationship (P<0.001). In conclusion, the study showed good correlation between mRNA-ISH and IHC, suggesting that mRNA-ISH can be a valuable tool in the assessment of the sensitivity and specificity of ER IHC assays.
AB - Immunohistochemical (IHC) quantification of estrogen receptor-α (ER) is used for assessment of treatment regimen in breast cancer. Different ER IHC assays may produce diverging results, because of different antibody clones, protocols, and stainer platforms. Objective tissue-based techniques to assess sensitivity and specificity of IHC assays are therefore needed. We tested the usability of ER mRNA-in situ hybridization (mRNA-ISH) in comparison with assays based on clones SP1 and 6F11. We selected 56 archival specimens according to their reported ER IHC positivity, representing a wide spectrum from negative to strongly positive cases. The specimens were used to prepare 4 TMAs with 112 cores. Serial sections of each TMA were stained for ER and pan-cytokeratin (PCK) by IHC and ESR1 (ER gene) by mRNA-ISH. Digital image analysis (DIA) was used to determine ER IHC H-score. ESR1 mRNA-ISH was scored both manually and by DIA. DIA showed a nonlinear correlation between IHC and ESR1 mRNA-ISH with R
2 -values of 0.80 and 0.78 for the ER antibody clones SP1 and 6F11, respectively. Comparison of manual mRNA-ISH scoring categories and SP1 and 6F11 IHC H-scores showed a highly significant relationship (P<0.001). In conclusion, the study showed good correlation between mRNA-ISH and IHC, suggesting that mRNA-ISH can be a valuable tool in the assessment of the sensitivity and specificity of ER IHC assays.
KW - estrogen receptor
KW - immunohistochemistry
KW - mRNA in situ hybridization
KW - specificity
UR - http://www.scopus.com/inward/record.url?scp=85063730291&partnerID=8YFLogxK
U2 - 10.1097/PAI.0000000000000760
DO - 10.1097/PAI.0000000000000760
M3 - Journal article
C2 - 30920963
SN - 1541-2016
VL - 28
SP - 347
EP - 353
JO - Applied Immunohistochemistry & Molecular Morphology
JF - Applied Immunohistochemistry & Molecular Morphology
IS - 5
ER -