Evaluation of HER-2/neu status in breast cancer specimens using immunohistochemistry (IHC) & fluorescence in-situ hybridization (FISH) assay.

Background & objectives: Fluorescence in situ hybridization (FISH) is increasingly being recognized as the most accurate and predictive test for HER2/neu gene amplification and response to therapy in breast cancer. In the present study we investigated HER-2/neu gene amplification by FISH in breast carcinoma tissue specimens and compared the results with that of immunohistochemical (IHC) analysis. Methods: A total of 90 breast carcinoma tissue samples were used for immunohistochemical (IHC) and FISH analysis. IHC was performed by using mouse monoclonal antibody to the intracellular domain of HER-2/neu protein. Each slide was scored in a blinded fashion by two pathologists according to the manufacturer's recommended criteria. FISH analysis was performed on paraffin embedded breast tumour tissue sections. The polysomy for centromere 17 (Spec green signal) was read as green signals less than 4 as moderate polysomy, and more than 4 as highly polysomy. Results: Thirty of the 90 patients had negative results by IHC and FISH. Of the 28 patients with the score of 2+ by IHC, 20 were FISH positive for HER-2/neu gene amplification, three were FISH negative and five patients showed equivocal (1.8-2.2) results by FISH. These five cases were retested for IHC and FISH on different paraffin embedded tissue blocks, and all five were found positive for HER-2/neu gene amplification. Twenty five patients with the score of 3+ by IHC were FISH positive for HER-2/neu gene amplification (>2.2). Seven cases with the score of 3+ by IHC were FISH negative for HER-2/neu gene amplification (>2.2), and showed polysomy of chromosome number 17 high polysomy > 4. Interpretation & conclusions: Our results indicated that HER-2/neu status by FISH should be performed in all cases of breast tumour with a 2+ score by IHC. Cases demonstrating a 3+ score by IHC may be subjected to FISH to rule out polysomy of chromosome 17 which could be falsely interpreted as HER-2/neu overexpression by IHC analysis. There is also a need for establishing a clinically validated cut-off value for HER-2/neu FISH amplification against IHC which may be further compared and calibrated.

Comparasion of two different detection methods for HER-2 protein expression and gene amplification in breast cancer tissue / 中华内分泌外科杂志

Objective To compare HER-2 state in breast cancer tissue deteced by fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) and analyze their correlation. Methods HER-2/neu protein expression and gene amplification were detected by FISH and IHC in 56 newly-diagnosed cases of female breast cancer from July 2008 to July 2009. Results Of the 56 patients, HER-2 protein expression (-), (+), (++), (+++) was 9 cases (16.1%), 29 cases (51.8%), 11 cases (19.6%) and 7cases (12.5%) respectively; 26 cases (46.4%) had HER-2 gene amplification while 30 cases (53.6%) didnt have. Type of HER-2 gene amplification was mainly HER-2(++) and HER-2(+++), and according gene amplification rate was 72 7% and 100%. HER-2 (+) gene amplification rate was 37.9 %(11cases) and no gene amplification was found in HER-2(-) tissue. The HER-2 positive rate using two methods had significant difference(χ2=19.778,P<0.01). HER-2(-) and HER-2(+++) had good consistency with the FISH results(Kappa=0.969),but HER-2(+) and HER-2(+ +) were poorly consistent with the FISH results(Kappa=0.271). Conclusions IHC is the preliminary screening method for detection of HER-2 expression. HER-2(-) and HER-2(+++) have good consistency with the gene amplification, and can guide clinical treatment. Some patients with HER-2(+) and HER-2(++) have HER-2 gene amplification. FISH is needed for targeted therapy.

Clinical Analysis of PTEN, p53 and Her-2/neu Expressions in Thyroid Cancers / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The dual-specificity phosphatase PTEN/ MMAC1/TEP1 has recently been identified as the tumor suppressor gene most frequently mutated and/or deleted in human tumors. However, PTEN mutations have rarely been detected in sporadic thyroid cancers. Therefore, this study investigated the PTEN expression of thyroid cancer and the relationship between PTEN, clinical status and other biologic factors such as HER-2/neu and p53. MATERIALS AND METHODS: The study samples consisted of 62 thyroid cancer specimens and 24 benign thyroid tumor specimens from patients who were operated on the Department of Surgery, Uijongbu St. Mary's hospital during the 5 years from January 1995 until January 2000. All tumors were studied by immunohistochemical staining using monoclonal antibodies against PTEN, HER-2/neu and p53. The results were analyzed statistically. RESULTS: PTEN protein was found to be under-expressed more frequently in thyroid cancers (29%) than in benign thyroid tumors (4.2%). The reduction in PTEN expression in thyroid cancers was not significantly related with the recorded clinical factors such as size, age, lymph node metastasis and p53, except for HER-2 which was found to be significantly related (p=0.001). HER-2 over- expression was noted in thyroid cancer (83.8%) more frequently than in benign tumors (16.7%). CONCLUSION: This study has demonstrated that the under-expression of PTEN protein and the over-expression of HER-2 protein may play a role in the carcinogenesis and development of thyroid cancer.

HER-2/neu gene amplification and expression in nasopharyngeal carcinoma and their clinical significance / 中国癌症杂志

Purpose:To study HER-2/neu gene amplification and expression in nasopharyngeal carcinoma (NPC) and their clinical significance.Methods:HER-2/neu gene amplification and expression in NPC tissues were detected with fluorescence in situ hybridization (FISH,Vysis PathVysion TM kit) and reverse transcription polymerase chain reaction (RT-PCR) and immounhistochemistry (IHC,DAKO Herceptin Test TM kit).Results:No HER-2/neu gene amplification but gene overexpression was detected in NPC. HER-2/neu overexpression was caused by mRNA overexpression.Conclusions:HER-2/neu gene has not been amplified,but overexpressed,thus HER-2/neu gene overexpression did not show prognostic significance in NPC.