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

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.

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.

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.

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