Correlation Between The Expression Of ERCC2 And P53 In Advanced Gastric Cancer With Platinum Drugs

Background and Purpose: In our country advanced gastric cancer lead to higher morbidity and mortality. For advanced gastric cancer, systemic chemotherapy is the primary treatment. However, many patients resistance to chemotherapeutic drugs, leading to disease progression, shortened survival time. The platinum-based doublets or triplets is taken in the treatment of advanced gastric. After into the body, platinum drugs act on DNA, and the DNA strand guanine nucleotide base ligand to form adducts, formed in Pt-DNA strand cross-linking, between Pt-DNA strand cross-linking or protein and Pt-DNA adduct formation of platinum-DNA polymer, impede replication and transcription, leading to tumor cell apoptosis. Nucleotide excision repair in vivo repair the DNA damage caused by platinum drugs. ERCC2 protein as a helicase by Excision repair cross complementing gene 2 encoding, can identify DNA damage site, unlock the damaged double helix, repair DNA damage. P53 gene is involved in the nucleotide excision repair process, and it has the function of regulating cell cycle and inducing apoptosis. This is related to the drug resistance of platinum drugs. In this study, the expression of ERCC2 and P53 in gastric carcinoma is detected by immunohistochemistry,and it is relate to the curative effect of chemotherapy with platinum drugs. It is hoped to be used to guide the individualized treatment of gastric cancer.Methods:The immunohistochemical method was used to detect the expression of ERCC2 and P53 protein in 56 patients with advanced gastric cancer. The patients were treated with chemotherapy by platinum based regimens.The overall remission rate was calculated, and the overall survival time(OS) and progression free survival(PFS) were recorded and analyzed statistically.Results : In all 56 cases of patients with advanced gastric, the expression of ERCC2 was positive in 11 cases and it of P53 was positive in 32 cases. Expression of ERCC2 and P53 were positive in 7 cases. The expression of P53 and ERCC2 had no correlation with age,sex and tumor differentiation(P> 0.05). No correlation between the expression of both ERCC2 and P53. In 56 patients after chemotherapy, including 1 cases of CR, 25 cases of PR,22 cases of SD and 8 cases of PD. The overall remission rate of ERCC2 positive expression was 18.2%, and the overall remission rate of negative expression was 53.3%. The overall remission rate of P53 positive expression was 34.4%, and that of negative expression was 62.5%. The overall remission rates of ERCC2 and P53 positive expression were lower than those of negative expression.(P<0.05). Median progression-free survival with positive expression of ERCC2 was 6 months,and it was 8 months with negative expression. Median progression-free survival with positive expression of P53 was 6 months,and it was 9 months with negative expression. The positive expression of ERCC2 in median overall survival was 10 months, and the negative expression of median overall survival was 15 months. The positive expression of P53 in median overall survival was 10 months, and the negative expression of median overall survival was 19 months. The median overall survival of the ERCC2 and P53 negatives was longer than the positives(P<0.05),and the median progression-free survival of the P53 positives was shortened(P<0.05).Conclusion: Patients with ERCC2 and P53 positive expression had lower remission rate. The overall survival of ERCC2 and P53 negative expression were longer than that of positive expression. The progression free survival of P53 negative expression was longer than that of positive expression. The expression of ERCC2 and P53 can used as an indicator to judge to chemotherapy efficacy by platinum drugs and prognosis of gastric cancer.