Dual-color silver-enhanced in-situ hybridization for determination of HER2 gene amplification in gastric carcinoma / 中华病理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the concordance of dual-color silver enhanced in-situ hybridization (DSISH) and immunohistochemistry (IHC) in the detection of HER2 gene amplification and expression and to evaluate the values of DSISH in detecting HER2 gene status in gastric carcinoma.</p><p><b>METHODS</b>By using automated DSISH and IHC, HER2 gene status was detected in 230 cases of gastric cancer.</p><p><b>RESULTS</b>Among the 230 cases of gastric carcinoma tested by DSISH, 43 cases were positive and 187 cases were negative; HER2 gene amplification rate was 18.7% (43/230). The expression of HER2 protein was negative, weakly, moderately and strongly positive in 115, 69, 15 and 31 cases, respectively, by IHC. HER2 protein positive rate was 13.5% (31/230). Of the 43 HER2 gene amplification cases by DSISH, 2, 10, 2 and 29 cases were negative, weakly, moderately and strongly positive by IHC; Of the 187 HER2 negative cases by DSISH, 113, 59, 13 and 2 cases were negative, weakly, moderately and strongly positive by IHC, respectively. The overall concordance of HER2 status in the investigation between IHC and DSIDH was 93.5% (201/215), with a high consistency (Kappa coefficient 0.767, P < 0.01).</p><p><b>CONCLUSIONS</b>DSISH can be applied to detect the HER2 gene status in gastric cancer and it also has a high consistency with the result of IHC. In addition, due to frequent heterogeneous expression of HER2, cases with moderate HER2 protein expression may need further assessment by DSISH.</p>