Reflex Repeat HER2 Testing of Grade 3 Breast Carcinoma at Excision Using Immunohistochemistry and In Situ Analysis: Frequency of HER2 Discordance and Utility of Core Needle Biopsy Parameters to Refine Case Selection.
Author(s): Prendeville S, Feeley L, Bennett MW, O'Connell F, Browne TJ
Publication: Am J Clin Pathol, 2016, Vol. 145, Page 75-80
PubMed ID: 26712873 PubMed Review Paper? No
Purpose of Paper
This paper investigated the accuracy of core needle biopsies for determining the human epidermal growth factor receptor 2 (HER-2) status and grade of breast carcinomas by comparing results in HER-2 negative biopsies with matched surgical resection specimens.
Conclusion of Paper
Of the 100 cases, 30 were upgraded from grade 2 to grade 3 after examination of the surgical specimen. Only 3 of the 100 biopsies classified as HER-2 negative or equivocal based on examination of the biopsy were found to be HER-2 positive after surgical resection. Importantly, in two of these cases there was heterogeneity in the FISH HER-2 amplification status within the tumor.
Studies
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Study Purpose
This study investigated the effect of examining the surgical resection specimen on the assigned tumor grade of HER-2 negative CNB specimens. One hundred cases were selected based on having been classified as HER-2 negative in the CNB and having an end-diagnosis of a grade 3 carcinoma. For these cases, morphology data were compared between matched surgical specimens and CNB. All specimens were processed and scored following ASCO/CAP guidelines.
Summary of Findings:
Of the 100 cases, 30 were initially characterized as grade 2 tumors but subsequently upgraded to grade 3. Of these 30 cases, 20 were upgraded after a higher mitotic index was assigned for the surgical specimen and the remaining 10 cases were upgraded based on a combination of higher mitosis score and nuclear pleomorphism (8 cases) or tubule formation (2 cases) in the excision specimen. Heterogeneity in the morphology (invasive ductal carcinoma and micropapillary carcinoma) was observed in only 4 cases.
Biospecimens
Preservative Types
- Formalin
Diagnoses:
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform Morphology H-and-E microscopy Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Biospecimen heterogeneity Entire tumor examined
Intratumoral sampling (exact positions not specified)
Biospecimen Acquisition Method of tissue acquisition Core needle biopsy
Surgical resection
-
Study Purpose
This study investigated the accuracy of CNB for determining the HER-2 status of breast tumors by comparing results in HER-2 negative biopsies with matched surgical resection specimens. One hundred cases were selected based on having been classified as HER-2 negative in the CNB and having an end diagnosis of a grade 3 carcinoma. For these cases, IHC and FISH data were compared between matched surgical specimens and CNB. All specimens were processed and scored following ASCO/CAP guidelines.
Summary of Findings:
Only 3 of the 100 biopsies classified as HER-2 negative or equivocal based on biopsy were found to be HER-2 positive after surgical resection. In two of these cases, HER-2 FISH was performed on the CNB and the HER-2/chromosome 17 ratio increased from 1.40 and 1.50 to 2.49 and 2.42, respectively in the excision specimens. Importantly, in both of these cases there was heterogeneity in the FISH HER-2 amplification status within the tumor. The third case was assigned a HER-2 IHC score of 1+ in the CNB and 2+ in the surgical specimen. A fourth case was found to have HER-2 amplification in <5% of the tumor, but as the area of HER-2 amplification was <10% of the tumor this was not considered to be true HER-2 amplification.
Biospecimens
Preservative Types
- Formalin
Diagnoses:
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform Protein Immunohistochemistry DNA FISH Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Biospecimen heterogeneity Intratumoral sampling (exact positions not specified)
Entire tumor examined
Biospecimen Acquisition Method of tissue acquisition Core needle biopsy
Surgical resection