ERCC1 mRNA levels as a useful prognostic biomarker for extrahepatic cholangiocarcinoma with R0 resection.

Abstract

239 Background: To date, no prognostic biomarker for biliary tract carcinoma has been identified. In previous studies of biliary tract carcinoma, no reliable data was found due to the varying composition of the cancer type (gallbladder, cholangiocarcinoma, and ampullary carcinoma), differences in tumor location, a mixture of curative and non-curative operations, and differences in operative methods. Methods: Fifty extrahepatic cholangiocarcinoma patients who underwent a pancreatoduodenectomy with R0 resection at the Tokyo Women’s Medical University Hospital were examined. All patients were pathologically diagnosed as having papillary or tubular adenocarcinoma. T-RNA was extracted from FFPE samples, and mRNA expression levels were measured by real-time RT-PCR. Results: In the preliminary analysis, 10 patients who have survived more than 5 years (LS group) and 10 patients who had a relapse within 2 years (SS group) were selected. EGFR, AREG, EREG, MMP-9, CDH-1, PARP1, and ERCC1 mRNA expression were examined; only the ERCC1 mRNA levels showed a significant difference between the LS and SS groups (median ERCC1: LS 26.5 vs. SS 9.7, p=0.0073). The median survival time (MST) of the patients with high ERCC1 levels was significantly higher than that in patients with a low ERCC1 level (MST: not reached vs. 16M). Then, 30 more patients with the same backgrounds were added to the study, and ERCC1 mRNA levels were measured in all 50 patients. The patients with high ERCC1 mRNA levels had a significantly greater overall survival rate compared with those with low ERCC1 levels (MST: not reached vs. 12.5M, 5-year survival rate: 92% vs 51%; p=0.04). In multivariate analysis, no lymph node metastases or high ERCC1 expression were significantly associated with better overall survival. Conclusions: ERCC1 mRNA expression seemed to be a useful prognostic biomarker for extrahepatic cholangiocarcinoma with R0 resection.