Evaluating HER2 Gene Amplification Using Chromogenic In Situ Hybridization (CISH) Method In Comparison To Immunohistochemistry Method in Breast Carcinoma

Abstract

BACKGROUND:In patients with breast cancer, HER2 gene expression is of a great importance in reacting to Herceptin treatment. To evaluate this event, immunohistochemistry (IHC) has been done routinely on the basis of scoring it and so the patients were divided into 4 groups. Lately, as there have been disagreements about how to treat score 2 patients, chromogenic in situ hybridization (CISH) and florescence in situ hybridization (FISH) are introduced. Since CISH method is more convenient than FISH for gene amplification study, FISH has been substituted by CISH.AIM:The current study is conducted in order to investigate whether using CISH is a better method comparison to IHC method for determines HER2 expression in patients with breast cancer in.METHODS:In this cross-sectional descriptive analytical study, information of 44 female patients with invasive ductal breast cancer were gathered from Imam Reza and Omid Hospital in Mashhad. IHC staining was done for all patients in order to determine the level of HER2 expression, and after scoring them into 4 groups of 0, +1, +2 and +3, CISH staining was carried out for all 4 groups. At the end, results from both methods were statistically evaluated using SPSS software V.22.0.RESULTS:The average age of patients was 50.2 with the standard deviation of 10.96. Using IHC method was observed that 2.6% (1 patient), 26.3% (10 patients), 65.8% (25 patients) and 5.3% (2 patients) percentage of patients had scores of 0, +1, +2 and +3. On the other hand, CISH method showed 36 patients (90%) with no amplifications and 4 (10%) with sever amplifications. In a comparative study using Fisher’s exact test (p = 0.000), we found a significant relation between IHC method and CISH method indicating that all patients showing severe amplifications in CISH method, owned scores of +2 and +3 in IHC method.CONCLUSION:According to the present study and comparing the results with similar previous studies, it can be concluded that CISH method works highly effective in determining HER2 expression level in patients with breast cancer. This method is also able to determine the status of patients with score +2 in IHC for their treatment with herceptin.

BRAF mutation, TERT promoter mutation, and HER2 amplification in sporadic or neurofibromatosis‐related neurofibromas and malignant peripheral nerve sheath tumors: do these molecules have a signature in malignant transformation?

“…Other bright-field assays like chromogen ISH (C-ISH), silver-enhanced ISH, and dual ISH are alternative methods to FISH (12). C-ISH is a preferable method to FISH that has advantages such as being cheaper than FISH, not requiring fluorescence microscope, and results are easier to archive (24). Membranous HER2 immunoexpression and gene amplification show a good correlation in breast tumors, but it is challenging to evaluate membranous positivity in soft tissue tumors because of undetectable cytoplasmic borders.…”

HER2/positive and HER2/low in inflammatory breast cancer recurrence

“…In situ hybridization is proposed as the preferred method for HER2 gene testing because of its advantages over IHC [ 23 , 24 ]. We used different samples to determine the number of current copies of a specific region of DNA for distinct locus rearranged as part of chromosomal changing [ 25 ].…”

Potential of modern circulating cell-free DNA diagnostic tools for detection of specific tumour cells in clinical practice

“…If tissue biopsy is possible, in situ hybridization (ISH) technique enables visual processing of mutation carrying cells through chromophore (chromogenic in situ hybridization - CISH) or fluorophore (fluorescence in situ hybridization - FISH). In situ hybridization technique is a technique where a probe – labelled single-stranded DNA or RNA – selectively binds to a specific target site of the cellular DNA or RNA ( 27 ). Detection can be performed through chromogenic or fluorescent signal analysis.…”