Estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression in breast cancer FNA cell blocks and paired histologic specimens: A large retrospective study.
BACKGROUND
Molecular analysis represents an increasingly important component of the pathologic examination of tumor specimens. Notably, the characterization of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression in breast cancer specimens provides critical prognostic and predictive information. The objective of the current study was to compare the concordance of these markers as determined on fine-needle aspiration (FNA) cell blocks compared with tissue blocks prepared from surgical specimens.


METHODS
A total of 134 cases of breast carcinoma were identified from 2002 through 2014 with both FNA cell blocks (fixed in 10% formalin) and corresponding available tissue blocks and ER, PR, and HER2 were characterized in both specimens. Negative and positive concordances were determined for ER and PR in cell blocks compared with tissue blocks, and for HER2 immunohistochemistry on cell blocks and tissue blocks versus the corresponding reference method, fluorescence in situ hybridization (FISH).


RESULTS
Concordance for ER expression evaluated on a cell block compared with the corresponding tissue block was 96.2%. Concordance for PR expression was 77.5%. Overall agreement of HER2 FISH testing between cell blocks and tissue blocks was 96.7%. For both cell blocks and tissue blocks, HER2 expression by immunohistochemistry demonstrated ≥98% positive and negative concordance with the FISH reference method.


CONCLUSIONS
ER, PR, and HER2 determination on FNA-acquired cell block (fixed exclusively in 10% formalin) showed excellent agreement for ER and HER2 and moderate agreement for PR with the corresponding tissue block. These findings support the equivalency of ER and HER2 evaluation performed on FNA cell blocks compared with surgical tissue blocks. Cancer Cytopathol 2016;124:828-35. © 2016 American Cancer Society.
Department of Pathology, University of California at San Francisco, San Francisco, California.
Poonam
P
Vohra
Department of Pathology, University of California at San Francisco, San Francisco, California.
Benjamin
B
Buelow
Department of Pathology, University of California at San Francisco, San Francisco, California.
Yunn-Yi
YY
Chen
Department of Pathology, Kaiser Permanente Medical Center, San Francisco.
Maria
M
Serrano
ECC, Burlingame, California.
Manjiv Singh
MS
Vohra
Cell Netix Pathology and Laboratories, Swedish Cancer Institute.
Anna
A
Berry
Department of Pathology, University of California at San Francisco, San Francisco, California.
Britt-Marie
BM
Ljung
D014408:Biomarkers, Tumor; D044963:Biopsy, Fine-Needle / Q000379:methods; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D005784:Gene Amplification; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017404:In Situ Hybridization, Fluorescence; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
breast cancer; estrogen receptor (ER); fluorescence in situ hybridization (FISH); human epidermal growth factor receptor 2 (HER2); immunohistochemistry; progesterone receptor (PR)