Study of differential polymerase chain reaction of C-erbB-2 oncogene amplification in gastric cancer.

ABSTRACT

AIM:To study the significance of C-erbB-2 oncogene amplification in gastric cancer.METHODS:C-erbB-2 oncogene amplification was examined by using differential polymerase chain reaction (dPCR) in surgical and endoscopic specimens of 83 cases of gastric cancer and 101 metastatic lymph nodes.RESULTS:C-erbB-2 amplification was found in 28.9% (24/83) surgical specimens and 20.5% (17/83) endoscopic ones of gastric cancer patients.The amplification was significant in both types of specimens of advanced cancer cases (P < 0.05) and surgical specimens with lymph node metastasis (P <0.01). The incidence of C-erbB-2 amplification in lymph nodes with metastasis was higher than in primary sites (surgical specimens, P < 0.05). The patients with amplification tumors had poorer 5-year survival rates than those with unampli-fication ones in the early cancers and well to moderately differentiated adeno-carcinomas (P <0.05). The same surgical samples were tested again by Southern blot hybridization to ascertain C-erbB-2 amplification, and the positive rate of C-erbB-2 amplification (15.7%) was lower than that of dPCR (28.9%, P < 0.05).CONCLUSION:Examining C-erbB-2 amplification by dPCR is a quick, simple, reliable and independent method, and is helpful in predicting prognosis and metastatic potential of gastric cancer.