Background: HER2/neu is a predictive biomarker for treatment of gastric cancer using trastuzumab in combination with chemotherapy. This study aimed to: (1) assess the amplification and the overexpression of HER2/neu using fluorescence in situ hybridization (FISH) and immunohistochemistry in gastric cancer; (2) survey the association between HER2/neu and clinicopathologic characteristics of gastric cancer. Patients and methods: one hundred and sixty gastric cancer patients were assessed HER2/neu overexpression by IHC using Ventana anti-HER-2/neu (4B5) kit and were assessed HER2/neu gene amplification by FISH using PathVysionTM HER-2 DNA Probe kit with biopsy specimens.
Results: HER2/neu protein expression rates of IHC 0, 1+, 2+ and 3+ were 70%, 10.6%, 10.6% and 8.8%, respectively. HER2/neu gene amplification was identified in gastric cancer from 21 out of 160 (13.1%) patients. The concordance between IHC and FISH was 90.0%. The HER2/neu-positive rate assessed by both techniques was 13.1%. There was a significant difference in HER2/neu-positivity between cardia gastric cancer and non-cardia gastric cancer (36.4% vs 11.4%, p = 0.040); between intestinal type and diffuse type (20.7% vs 5.9%, p = 0.010); between well, moderately differentiated and poorly differentiated gastric cancer (18.6% and 23.8% vs 5.8%, p = 0.047). Conclusion: We applied successfully FISH and IHC technique with biopsy samples in gastric cancer detecting HER2/neu positivity in order to select patients that benefit from trastuzumab in combination with chemotherapy. HER2/neu status associated with tumor location, Lauren classification and differentiated grading.
Keywords: gastric cancer, fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), HER-2/neu
Evaluation of Myc Gene Amplification in Prostate Cancer Using a Dual Color Chromogenic in-Situ Hybridization (Dual CISH) Assay
