Original Article

Comparison of Immunohistochemical Methods (IHC) and Fluorescent in Situ Hybridization (FISH) in the Detection of HER2 /Neu Gene in Kurdish Patients with Breast Cancer in Western Iran

Abstract

 

Background: Amplification of HER2 is an important factor in the diagnosis and treatment of breast cancer. Fluorescence in situ hybridization (FISH) is the gold standard for the detection of HER2-positive tumors. However, the Immunohistochemistry (IHC) assay for the detection of HER2 is more popular in the preclinical laboratory since it is faster and more economical compared to the FISH test.

Materials and Methods: In this study, the status of HER2 amplification is determined by the FISH test using 44 formalin-fixed paraffin-embedded tissue samples and comparing the results with the IHC test to determine the reliability of the IHC test. Also, the relationship between HER2 amplification and estrogen, progesterone receptors, P53, age, menopausal status, family history of breast cancer, tumor size, and histological grade were determined.

Results: Examination of HER2 in 44 samples by IHC showed 3 (6.8%) and 5 (11.4%) samples were positive (IHC 3+) and negative (IHC 0, 1+), respectively, and 36 (81.8%) samples were ambiguous (IHC 2 +), but examination by FISH showed 21 samples (47, 7%) were positive and 23 samples (52, 3%) were negative. There was a significant difference between IHC and FISH in the detection of HER2 amplification (P=0.019). Also, there was a significant difference between HER2 amplification and menopause in patients (P=0.035).

Conclusion: This result demonstrated that the IHC test is not a reliable test to determine HER2 amplification. This study represented that FISH analysis is more reliable than IHC and must be preferentially performed for all cases, especially for HER2 +2 cases for whom the IHC result is 2+.

1. Bethune GC, Pettit AS, Veldhuijzen van Zanten D, et al. Well‐differentiated invasive breast cancers with equivocal HER 2 immunohistochemistry: what is the yield of routine reflex in‐situ hybridization testing? Histopathology. 2017;70(6):966-74.
2. DeSantis CE, Fedewa SA, Goding Sauer A, et al. Breast cancer statistics, 2015: Convergence of incidence rates between black and white women. CA Cancer J Clin. 2016;66(1):31-42.
3.Patnayak R, Jena A, Rukmangadha N, et al. Hormone receptor status (estrogen receptor, progesterone receptor), human epidermal growth factor-2 and p53 in South Indian breast cancer patients: A tertiary care center experience. Indian J Med Paediatr Oncol. 2015;36(2):117-22.
4. Jazayeri SB, Saadat S, Ramezani R, et al. Incidence of primary breast cancer in Iran: Ten-year national cancer registry data report. Cancer Epidemiol. 2015;39(4):519-27.
5. Swain SM, Baselga J, Kim S-B, et al. Pertuzumab, trastuzumab, and docetaxel in HER2-positive metastatic breast cancer. N Engl J Med. 2015;372(8):724-34.
6. Loibl S, Gianni L. HER2-positive breast cancer. Lancet. 2017;389(10087):2415-2429.
7.Tolaney SM, Barry WT, Dang CT, et al. Adjuvant paclitaxel and trastuzumab for node-negative, HER2-positive breast cancer. N Engl J Med. 2015;372(2):134-41.
8. Wolff AC, Hammond MEH, Hicks DG, et al. Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists clinical practice guideline update. J Clin Oncol. 2013;31(31):3997-4013
9.Lin CS, Chang SC, Ou LH, et al. Mitochondrial DNA alterations correlate with the pathological status and the immunological ER, PR, HER-2/neu, p53 and Ki-67 expression in breast invasive ductal carcinoma. Oncol Rep. 2015;33(6):2924-34.
10.Peng JH, Zhang X, Song JL, et al. Neoadjuvant chemotherapy reduces the expression rates of ER, PR, HER2, Ki67, and P53 of invasive ductal carcinoma. Medicine (Baltimore). 2019;98(2):e13554.
11. Huang C, Chen Y, Wang M, et al. HER-2/neu overexpression in Chinese breast cancers: correlation with other prognostic factors. J Formos Med Assoc. 1995;94(11):660-5.
12. Sirati F, Yadegari K. Determination of the Correlation between Her-2 Tumor Factor and Invasion of Breast Cancer to Axillary Lymph Nodes in Patients Undergoing Mastectomy in Cancer Institute (2001-2003). RJMS. 2004;11(43):781-7.
13. Agersborg S, Mixon C, Nguyen T, et al. Immunohistochemistry and alternative FISH testing in breast cancer with HER2 equivocal amplification. Breast Cancer Res Treat. 2018;170(2):321-328.
14. Gunn S, Yaziji H, Sims C, et al. Abstract P1-09-18: A clinically validated DNA microarray for high-resolution HER2 testing defines a new genomic subtype in high-risk breast cancer with equivocal results by IHC and FISH. Cancer Res. 2017; 77 (4_Supplement): P1-09-18.
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IssueVol 16, No 4 (2022) QRcode
SectionOriginal Article(s)
DOI https://doi.org/10.18502/ijhoscr.v16i4.10879
Keywords
Breast cancer; Fluorescence in situ hybridization (FISH); Human epidermal growth factor receptor-2 (HER2); Immunohistochemistry
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Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
1.
Aznab M, Izadi B, Amirian F, Khazaei S, Madani SH, Ramezani M. Comparison of Immunohistochemical Methods (IHC) and Fluorescent in Situ Hybridization (FISH) in the Detection of HER2 /Neu Gene in Kurdish Patients with Breast Cancer in Western Iran. Int J Hematol Oncol Stem Cell Res. 2022;16(4):217-223.