6652 Comparison of fluorescence in situ hybridization and dual colour chromogenic in situ hybridization for the assessment of HER2 status on gastric cancer biopsies

Background: HER-2/neu is a predictive biomarker for treatment of gastric cancer using trastuzumab in combination with chemotherapy. This study aimed to evaluate the status of HER-2/neu gene amplification using fluorescence in situ hybridization (FISH) in gastric cancer. Patients and methods: thirty six gastric cancer patients were assessed HER-2/neu gene amplification by FISH using PathVysionTM HER-2 DNA Probe kit (including HER-2/neu probe and CEP-17 probe) with biopsy and surgical specimens. Results: The HER-2/neu gene amplification was observed in three cases (8.3%), the HER-2/neu gene amplification rate in Lauren’s intestinal-type and diffuse-type were 11.8% and 5.2%, respectively. Conclusion: We applied successfully FISH technique with gastric cancer tissue samples. This technique could be performed as routine test in gastric cancer in order to select patients that benefit from trastuzumab in combination with chemotherapy.

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Detection of HER2 Amplification in Breast Carcinomas: Comparison of Multiplex Ligation-Dependent Probe Amplification (MLPA) and Fluorescence In Situ Hybridization (FISH) combined with Automated Spot Counting

Analytical Cellular Pathology ◽

10.1155/2006/741586 ◽

2006 ◽

Vol 28 (4) ◽

pp. 151-159

Author(s):

Elna Moerland ◽

Rens L. H. P. M. van Hezik ◽

Toine C. J. M. van der Aa ◽

Mike W. P. M. van Beek ◽

Adriaan J. C. van den Brule

Keyword(s):

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Gene Amplification ◽

Her2 Status ◽

Her2 Amplification ◽

Breast Carcinomas ◽

Her2 Gene ◽

Her2 Gene Amplification ◽

Dependent Probe

In this study the detection of HER2 gene amplification was evaluated using Fluorescence In Situ Hybridization (FISH; PathVysion) in comparison with Multiplex Ligation-dependent Probe Amplification (MLPA), a PCR based technique. These two methods were evaluated on a series of 46 formalin fixed paraffin embedded breast carcinomas, previously tested for protein overexpression by HercepTest (grouped into Hercep 1+, 2+ and 3+). HER2 gene amplification (ratio ≥ 2.0) by FISH was found in 9/10, 10/30 and 0/6 in IHC 3+, 2+ and 1+/0 cases, respectively. Digitalized automated spot counting performed with recently developed CW4000 CytoFISH software was 100% concordant with manual FISH scoring. Using MLPA 18/46 samples showed a clear HER2 amplification. Comparing MLPA and IHC showed the same results as for FISH and IHC. All but one FISH positive cases (18/19) were confirmed by MLPA for the presence of the gene amplification. The overall concordance of detection of Her2 gene amplification by FISH and MLPA was 98% (45/46). Furthermore, both the level of amplification and equivocal results correlated well between both methods. In conclusion, MLPA is a reliable and reproducible technique and can be used as an either alternative or additional test to determine HER2 status in breast carcinomas.

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