ERCC1 mRNA expression as a postoperative prognostic marker in extrahepatic bile duct cancer.

BACKGROUND: No reliable biomarker for biliary tract cancer has yet been identified because of the varying composition of the cancer type, differences in tumor location, a mixture of curative and non-curative operations, and differences in operative methods.

METHODS: Fifty extrahepatic bile duct cancer patients, pathologically diagnosed with papillary or tubular adenocarcinoma who underwent a pancreatoduodenectomy with R0 resection, were included in the study. Messenger RNA (mRNA) expression levels were measured from formalin-fixed, paraffin-embedded samples by real-time reverse-transcription polymerase chain reaction.

RESULTS: The preliminary analysis selected ten patients who have survived more than 5 years (LS group) and ten who had a relapse within 2 years (SS group). mRNA expression of seven target genes was examined, but only excision repair cross-complementing 1 (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 of patients with high ERCC1 levels was significantly longer than in patients with low ERCC1 levels (p = 0.0105). Thirty more patients with identical backgrounds were added to the study, and ERCC1 mRNA levels were measured in all 50 patients. Those with high ERCC1 mRNA levels had a significantly greater overall survival (OS) time compared with those with low ERCC1 levels (MST: 174 vs. 86 M; p = 0.048). Multivariate analysis found that an absence of lymph node metastases and high ERCC1 expression were significantly associated with improved OS.

CONCLUSION: ERCC1 mRNA expression appears to be a useful prognostic biomarker for extrahepatic bile duct cancer with R0 resection.