Expression of p53 and c-erbB-2 Proteins as a Prognostic Factor in Patients with Gastric Carcinomas

ABSTRACT

Gastric cancer is not only one of the most common cancers in the world but also one of the most important malignant tumors in terms of incidence in Korea. In spite of it's clinical significance, the mechanism of malignant transformation in the stomach has not yet been well characterized. Recent studies disclosed enormous data suggesting that the p53 protein and the c-erbB-2 proto-oncogene have a critical role in the tumorogenesis of gastric cancer. More recently, the expression of the p53 protein has been associated with increased proliferative activity, but serves as a poor prognostic indicator in the case of patients for whom aggressive adjuvant therapy is required. Amplification of the c-erbB-2 oncogene has also been reported in gastric cancer. In the case of breast cancer, it has been demonstrated that no close correlation exists between the c-erbB-2 expression and the prognosis. However, no reports describe the relation between c-erbB-2 expression, p53 expression, PCNA expression and the prognosis for patients with gastric cancer. So this study was done to evaluate the expression of the p53 and c-erbB-2 and to assess the prognostic value in patients eith gastric cancer. The results are as follows: 1) The overall expression rates for p53 and c-erbB-2 were 38% and 20%, respectively. 2) There was no close relation between the expression rate of p53 and the tumor size, the Borrmann type, the nodal involvement, distant metastasis, Ming's classification, or Lauren's classification. The expression rate of p53 was closely related the tumor stage. 3) The expression rate of p53 in tumors which expressed PCNA was higher than that in tumors which did not express PCNA (p5 cm) was higher than that in small tumors(0.05). 6) The overall cumulative 5-year survival rate in the positive expression group for c-erbB-2 was lower than that in the negative group and the difference was statistically significant(p<0.05). In conclusion, it is suggested that p53 expression can not used as a prognostic factor for gastric cancer, but c-erbB-2 may be such a prognostic factor.