Format

Send to

Choose Destination
Indian J Gastroenterol. 2019 Aug 10. doi: 10.1007/s12664-019-00955-6. [Epub ahead of print]

Could quantitative real-time polymerase chain reaction assay serve as an alternative test method to evaluate human epidermal growth factor receptor 2 status of gastric carcinoma in the South Asian setting?

Author information

1
Post Graduate Institute of Medicine, University of Colombo, Colombo, Sri Lanka.
2
Department of Pathology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
3
Department of Surgery, Faculty of Medicine, The National Hospital of Sri Lanka, University of Colombo/University Surgical Unit, Colombo, Sri Lanka.
4
Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, Colombo, Sri Lanka.
5
Department of Chemistry, Faculty of Science, University of Colombo, Colombo, Sri Lanka. rsdassanayake@chem.cmb.ac.lk.

Abstract

BACKGROUND:

Human epidermal growth factor receptor 2 (HER2) protein overexpression and/or HER2 gene amplification are/is linked to a dismal outcome of gastric carcinoma (GCa). Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are key methods to identify patients for HER2 targeted therapy. Drawbacks of both the methods warrant novel tests. Hence, we evaluated the value of quantitative real-time polymerase chain reaction (qPCR) as an alternative test method, relative to IHC to detect HER2 status of GCa and to find relationship between these  results with demographic/clinicopathological data.

METHOD:

Twenty GCa patients with known IHC HER2 scores were evaluated. qPCR was performed for the HER2 gene and amyloid precursor protein (reference gene) in formalin-fixed paraffin-embedded GCa tissue. Cycle threshold values (Ct) were analyzed using the Pfaffl method to detect HER2 gene amplification.

RESULTS:

HER2 positivity rates by IHC and qPCR were 20% and 35%, respectively. The sensitivity and specificity of qPCR were 67% and 76%, respectively, relative to IHC. qPCR results were reproducible. The diagnostic consistency between IHC and qPCR (κ = 0.146) was slightly agreeable (0.01 < k < 0.20), with a 65% concordance. Based on McNemar's test, there was no significant difference between the results of the two tests. IHC HER2 protein expression had relationship with the tumor (TNM) stage and Lauren histological type (p < 0.05). Positive HER2 gene expression by qPCR showed relationship with depth of invasion, lymph node involvement, and degree of differentiation (p < 0.05).

CONCLUSION:

Cost-effective qPCR could serve as an alternative test method for detection of HER2 status of GCa. Both HER2 overexpression by IHC and gene amplification by qPCR are associated with adverse clinicopathological features.

KEYWORDS:

Gastric carcinoma; HER2 status; Quantitative PCR assay

PMID:
31401730
DOI:
10.1007/s12664-019-00955-6

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center