Molecular biomarkers in extrahepatic bile duct cancer patients undergoing chemoradiotherapy for gross residual disease after surgery

Purpose: To analyze the outcomes of chemoradiotherapy for extrahepatic bile duct (EHBD) cancer patients who underwent R2 resection or bypass surgery and to identify prognostic factors affecting clinical outcomes, especially in terms of molecular biomarkers. Materials and Methods: Medical records of 21 patients with EHBD cancer who underwent R2 resection or bypass surgery followed by chemoradiotherapy from May 2001 to June 2010 were retrospectively reviewed. All surgical specimens were re-evaluated by immunohistochemical staining using phosphorylated protein kinase B (pAKT), CD24, matrix metalloproteinase 9 (MMP9), survivin, and beta-catenin antibodies. The relationship between clinical outcomes and immunohistochemical results was investigated. Results: At a median follow-up of 20 months, the actuarial 2-year locoregional progression-free, distant metastasis-free and overall survival were 37%, 56%, and 54%, respectively. On univariate analysis using clinicopathologic factors, there was no significant prognostic factor. In the immunohistochemical staining, cytoplasmic staining, and nuclear staining of pAKT was positive in 10 and 6 patients, respectively. There were positive CD24 in 7 patients, MMP9 in 16 patients, survivin in 8 patients, and beta-catenin in 3 patients. On univariate analysis, there was no significant value of immunohistochemical results for clinical outcomes. Conclusion: There was no significant association between clinical outcomes of patients with EHBD cancer who received chemoradiotherapy after R2 resection or bypass surgery and pAKT, CD24, MMP9, survivin, and beta-catenin. Future research is needed on a larger data set or with other molecular biomarkers.