The Assessment of<i>HER2</i>Gene Status by Fluorescence In Situ Hybridization in Invasive Breast Carcinomas With Equivocal HER2 Immunostaining: Experience From a Single Institution

Efared, Boubacar; Sidibé, Ibrahim S.; Gamrani, S.; Otmani, Ihsane El; Erregad, Fatimazahra; Hammas, Nawal; Bennis, S.; Chbani, Laïla; Fatemi, Hinde El

doi:10.1177/1066896918767546

Cited by 5 publications

(4 citation statements)

References 25 publications

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“…In this study, the mean age of patients with HER2 IHC score = 2+ tumors was 55.74 years, and most tumors (64.3%) were grade 2 in contrast to a Moroccan study, which showed a mean age of 49.51 years and a similar split of grade 2 (46.9%) and 3 (42.7%) tumors 10 . No correlation was demonstrated among age, tumor grade, Ki67 or hormone receptor status, and a positive HER2 FISH result in the current study.…”

Section: Discussioncontrasting

confidence: 82%

“…5,17,18 In this study, the mean age of patients with HER2 IHC score = 2+ tumors was 55.74 years, and most tumors (64.3%) were grade 2 in contrast to a Moroccan study, which showed a mean age of 49.51 years and a similar split of grade 2 (46.9%) and 3 (42.7%) tumors. 10 No correlation was demonstrated among age, tumor grade, Ki67 or hormone receptor status, and a positive HER2 FISH result in the current study. Efared et al 10 showed no differences with regard to age (P = 0.312), grade (P = 0.127), hormone receptor status (P = 0.110), and Ki67 (P = 0.319) between HER2 FISH-positive and negative cases.…”

Section: Discussioncontrasting

confidence: 65%

“…Of the HER2 IHC score = 2+ breast carcinomas referred for FISH in our study, 11.2% were confirmed FISH-positive and 81.7% were FISH-negative, as per the HER2 FISH report at the time of diagnosis. This is lower than the HER2 FISH-positive rates reported by Taylor et al 9 (23.3%), Efared et al 10 (22.5%), and Payandeh et al 11 (31%) described in Canada, Morocco and Iran, respectively. The lower FISH positivity observed in our study may be due to a number of factors, including tissue fixation, interobserver variability with HER2 IHC interpretation, study population differences, and difficulties interpreting FISH signals.…”

Section: Discussioncontrasting

confidence: 56%

“…No correlation was demonstrated among age, tumor grade, Ki67 or hormone receptor status, and a positive HER2 FISH result in the current study. Efared et al 10 showed no differences with regard to age ( P = 0.312), grade ( P = 0.127), hormone receptor status ( P = 0.110), and Ki67 ( P = 0.319) between HER2 FISH-positive and negative cases. Rushoff et al, 21 however, showed that histologic grading, hormone receptor status, histologic subtype, age, and nodal status had a significant effect on the FISH HER2 positivity rate using a multiple-testing model.…”

Section: Discussionmentioning

confidence: 92%

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HER2 Equivocal (Score = 2+) Breast Carcinoma Cases Identified by Immunohistochemistry at a South African Hospital. What is the Impact of Fluorescent In Situ Hybridization Testing?

Mohanlal

Bouwer

Willem

2023

Applied Immunohistochemistry &Amp; Molecular Morphology

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The American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP) guidelines are used for human epidermal growth factor receptor 2 (HER2) reporting in breast carcinoma. Cases that demonstrate weak to moderate complete membrane immunohistochemical staining in >10% of the tumor are scored as 2+ (equivocal). This study aimed to determine what proportion of HER2 immunohistochemistry (IHC) score = 2+ breast carcinomas were confirmed to be positive by HER2 fluorescent in situ hybridization (FISH). There were 241 HER2 IHC score = 2+ breast carcinomas included. Most (74.3%) carcinomas were estrogen and progesterone receptor-positive. Invasive breast carcinoma of no special type (89.2%) was the commonest histologic subtype. Most tumors were grade 2 (64.3%). As per the FISH report, at the time of diagnosis, 27 cases (11.2%) were HER2 FISH positive. All HER2 FISH equivocal cases and one FISH positive case assessed using the 2013 ASCO/CAP HER2 criteria were reclassified to HER2 FISH negative when the 2018 criteria were applied. There was a high level of agreement (κ = 0.979) between HER2 FISH results obtained using the 2013 and the 2018 criteria. This study provides insight into the frequency of HER2 FISH positivity (11.2%) among HER2 IHC score = 2+ breast carcinomas and the impact of modifications to the ASCO/CAP HER2 guidelines. Elimination of the HER2 FISH equivocal category by the 2018 guidelines has reduced the need for repeat testing and simplified clinical management. Reclassification of previous HER2 FISH positive to negative has resulted in some patients being ineligible for costly anti-HER therapy.

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Section: Discussioncontrasting

confidence: 82%