Clinical correlation of cadherin‐17 marker with advanced tumor stages and poor prognosis of cholangiocarcinoma

Background and Objectives In this retrospective study, we examined the CA17 tissue expression and analyzed its clinical significance in cholangiocarcinoma (CCA). Materials and Methods Immunohistochemistry was performed to assess CA17 expression on tissue microarrays in a training cohort enrolling 120 CCA patients and a validation cohort comprising 60 CCA patients. Image pro plus was applied to score the staining intensity and expression level of CA17 marker. Kaplan‐Meier analysis, Cox's proportional hazards regression, and nomogram were applied to evaluate the prognostic significance of CA17. Results CA17 cancer biomarker over‐expression was significantly observed in CCA compared to their non‐tumor counterparts, and positively correlated with aggressive tumor phenotypes, like lymph node metastasis. Meanwhile, patients with high expression of CA17 correlated with worse postoperative overall survival (OS) and recurrence‐free survival. Besides, multivariate analysis identified that CA17 expression was an independent prognostic factor for cholangiocarcinoma patients, which indicated that the CA17 could be more efficient than serum CA19‐9 in predicting the OS of CCA patients. Notably, the nomogram integrating CA17 expression had better prognostic performance as compared with current TNM staging systems. Conclusion CA17 was an independent adverse prognostic factor for CCA patients’ survival, which may serve as a promising prognostic biomarker for CCA patients.