DOI QR코드

DOI QR Code

Quantification of Her-2/Neu Gene in Breast Cancer Patients using Real Time-Polymerase Chain Reaction (Q-PCR) and Correlation with Immunohistochemistry Findings

  • Published : 2013.03.30

Abstract

Background: HER-2/neu is a proto-oncogene that encodes a transmembrane tyrosine kinase growth factor which is crucial for stimulating growth and cellular motility. Overexpression of HER-2/neu is observed in 10-35% of human breast cancers and is associated with pathogenesis, prognosis as well as response to therapy. Given the imperative role of HER-2/neu overexpression in breast cancer, it is important to determine the magnitude of amplification which may facilitate a better prognosis as well as personalized therapy in affected patients. In this study, we determined HER-2/neu protein expression by immunohistochemistry (IHC) concurrently with HER-2/neu DNA amplification by quantitative real time-polymerase chain reaction (Q-PCR). Materials and Methods: A total of 53 paired tissue samples from breast cancer patients were frozen-sectioned to characterize the tumour and normal tissues. Only tissues with 80% tumour cells were used in this study. For confirmation, Q-PCR was used to determine the HER-2/neu DNA amplification. Results: We found 20/53 (37.7%) of the tumour tissues to be positive for HER-2/neu protein overexpression using IHC. Out of these twenty, only 9/53 (17%) cases were in agreement with the Q-PCR results. The concordance rate between IHC and Q-PCR was 79.3%. Approximately 20.7% of positive IHC cases showed no HER-2/neu gene amplification using Q-PCR. Conclusion: In conclusion, IHC can be used as an initial screening method for detection of the HER-2/neu protein overexpression. Techniques such as Q-PCR should be employed to verify the IHC results for uncertain cases as well as determination of HER-2/neu gene amplification.

References

  1. Bofin AM, Ytterhus B, Martin C, et al (2004). Detection and quantitation of HER-2 gene amplification and protein expression in breast carcinoma. Am J Clin Pathol, 122, 110-9. https://doi.org/10.1309/8A2DJFT07NE6EWHE
  2. Carney WP, Leitzel K, Ali S, et al (2007). HER-2/neu diagnostics in breast cancer. Breast Cancer Res, 9, 207. https://doi.org/10.1186/bcr1664
  3. Denisov EV, Sukhanovskaya TV, Dultseva TS, et al (2011). Coordination of TP53 abnormalities in breast cancer:data from analysis of TP53 polymorphisms, loss of heterozygosity, methylation, and mutations. Genet Test Mol Biomarkers, 15, 901-7. https://doi.org/10.1089/gtmb.2011.0038
  4. Dowsett M, Hanby AM, Laing R, et al (2007). HER2 testing in the UK: consensus from a national consultation. J Clin Pathol, 60, 685-9. https://doi.org/10.1136/jcp.2006.044321
  5. Fehm T, Becker S, Duerr-Stoerzer S, et al (2007). Determination of HER2 status using both serum HER2 levels and circulating tumor cells in patients with recurrent breast cancer whose primary tumor was HER2 negative or of unknown HER2 status. Breast Cancer Res, 9, 74. https://doi.org/10.1186/bcr1783
  6. Goud KI, Dayakar S, Vijayalaxmi K, et al (2013). Evaluation of HER-2/neu satatus in breast cancer specimens using immunohistochemistry (IHC) and fluorescence in-situ hybridization (FISH) assay. Indian J Med Res. 135, 312-7.
  7. Gown AM (2008). Current issues in ER and HER2 testing by IHC in breast cancer. Mod Pathol, 21, 8-15. https://doi.org/10.1038/modpathol.2008.34
  8. Jemal A, Siegel R, Xu J, et al (2010). Cancer statistics, 2010. CA Cancer J Clin, 60, 277-300. https://doi.org/10.3322/caac.20073
  9. Lyon E (2001). Mutation detection using fluorescent hybridization probes and melting curve analysis. Expert Rev Mol Diagn 1, 92-1. https://doi.org/10.1586/14737159.1.1.92
  10. Mendoza G, Portillo A, Olmos-Soto J (2013). Accurate breast cancer diagnosis through real-time PCR her-2 gene quantification using imunohistochemically-identified biopsies. Oncol Letters. 5, 295-8.
  11. Metcalfe K, Lubinski J, Lynch HT, et al (2010). Family history of cancer and cancer risks in women with BRCA1 or BRCA2 mutations. J Natl Cancer Inst, 102, 1874-8. https://doi.org/10.1093/jnci/djq443
  12. Moelans CB, de Weger RA, Van der Wall E, et al (2011). Current technologies for HER2 testing in breast cancer. Crit Rev Oncol Hematol. 380-2.
  13. Nistor A, Watson PH, Pettigrew N, et al (2006). Real-time PCR complements immunohistochemistry in the determination of HER-2/neu status in breast cancer. BMC Clin Pathol, 6, 2. https://doi.org/10.1186/1472-6890-6-2
  14. Omar ZA., Mohd Ali Z, Tamin INS (2011). National Cancer Registry Report 2007. Ministry of Health, Malaysia. 78.
  15. Rosa FE, Silveira SM, Silveira CG, et al (2009). Quantitative real-time RT-PCR and chromogenic in situ hybridization:precise methods to detect HER-2 status in breast carcinoma. BMC Cancer, 9, 90. https://doi.org/10.1186/1471-2407-9-90
  16. Tse C, Brault D, Gligorov J, et al (2005). Evaluation of the quantitative analytical methods real-time PCR for HER-2 gene quantification and ELISA of serum HER-2 protein and comparison with fluorescence in situ hybridization and immunohistochemistry for determining HER-2 status in breast cancer patients. Clin Chem, 51, 1093-1. https://doi.org/10.1373/clinchem.2004.044305
  17. Wittwer CT, Ririe KM, Andrew RV, et al (1997). The LightCycler: a microvolume multisample fluorimeter with rapid temperature control. Biotechniques, 22, 176-1.

Cited by

  1. Modern methods in breast cancer diagnostics vol.8, pp.4, 2014, https://doi.org/10.1134/S1990750814040106
  2. ZKSCAN3 Upregulation and Its Poor Clinical Outcome in Uterine Cervical Cancer vol.19, pp.10, 2018, https://doi.org/10.3390/ijms19102859