Relationship between human epidermal growth factor receptor 2 gene amplification and protein expression and clinicopathological features of patients with gastric carcinoma

Objective To investigate the relationship between human epidermal growth factor receptor 2 (HER-2) gene amplification and protein expression in gastric carcinoma and its clinicopathological features. Methods Gene expression and protein expression of 98 gastric cancer patients were detected by fluorescence in situ hybridization (FISH), and immunohistochemistry (IHC) staining respectively. The relationship between gene amplification, protein expression of HER-2 and the clinicopathological characteristics were analyzed. Results In 98 cases of gastric cancer, there were 16.3% (16/98) with gene amplification of HER-2, 83.7% (82/98) without gene amplification of HER-2; 31.6% (31/98) with negative expression of HER-2 protein, 59.2% (58/98) with uncertain expression of HER-2 protein, 9.2% (9/98) with positive expression of HER-2 protein. The coincidence rates of HER-2 protein expression and gene amplification were 96.7% (30/31), 12.0% (7/58), 88.9% (8/9). The expression of HER-2 protein and gene amplification in gastric cancer was significantly correlated (P 0.05), but with lymph node metastasis (P= 0.022). Conclusions The negative and positive expression of HER-2 protein have a high coincidence rate with gene amplification in gastric carcinoma. However, the results of IHC and FISH are different when the expression of HER-2 protein is uncertain. The amplification of HER-2 gene is associated with lymph node metastasis in patients with gastric cancer, which may provide an important reference index for determining the biological behavior of gastric cancer. Key words: Gastric neoplasms; Receptor, epidermal growth factor; In situ hybridization, fluorescence; Immunohistochemistry; Lymph nodes