SerpinB3/4 Expression Is Associated with Poor Prognosis in Patients with Cholangiocarcinoma

Simple Summary Cholangiocarcinoma is characterized by a very poor outcome and SerpinB3, a serine protease inhibitor, has recently been found to play a relevant role in malignant transformation in different cancers. The aim of this study was to analyze the expression of this biomarker in the serum and surgical specimens of cholangiocarcinoma in relation to clinical outcome. High levels of SerpinB3/4 were detected in tumoral tissue in 12.2% of CCA, which were characterized by a more advanced TNM stage and lower overall patient survival, independently of CCA subclass. In addition, patients who had detectable free or IgM-linked SerpinB3/4 in serum showed poorer survival. In conclusion, the present study provides evidence that SerpinB3/4, both in the serum and in tumoral tissue, could be considered a useful biomarker to identify the small subgroup of CCA patients with more aggressive tumor biology and dismal prognosis.Abstract Cholangiocarcinoma (CCA), the second most common primary liver tumor, is associated with a dismal outcome, and useful prognostic markers are not currently available in clinical practice. SerpinB3, a serine protease inhibitor, was recently found to play a relevant role in malignant transformation in different cancers. The aim of the present study was to determine the expression of SerpinB3/4 in tissue and serum samples of patients with CCA in relation to clinical outcomes. SerpinB3/4 was assessed in the tissue microarrays (TMAs) of 123 surgically resected CCAs. ELISA assays were carried out in 188 patients with CCA to detect the free and IgM-linked forms of SerpinB3/4. Overall survival was analyzed in relation to SerpinB3/4 expression, and Cox models were used to identify the variables associated with survival. High levels of SerpinB3/4 (TMA score 2+/3+) were detected in 15 tumors (12.2%), characterized by a more advanced TNM stage (III/IV: 64.3% vs. 31.3%; p = 0.031) and lower overall patient survival, independently of CCA subclass (intrahepatic CCA: median 1.1 (0.8-Not Estimable, NE) vs. 2.4 (1.8-3.4) years; p = 0.0007; extrahepatic CCA: median 0.8 (0.2-NE) vs. 2.2 (1.5-5.4) years; p = 0.011). Vascular invasion (p = 0.027) and SerpinB3/4 scores (p = 0.0016) were independently associated with mortality in multivariate analysis. Patients who had detectable free or IgM-linked SerpinB3/4 in their serum showed poorer survival (1 vs. 2.4 years, p = 0.015, for free SerpinB3/4, and 1 vs. 2.6 years, p = 0.0026, for SerpinB3/4-IgM). In conclusion, high levels of SerpinB3/4 in tissue and serum in CCA are associated with poor outcomes after surgery, regardless of tumor subclass.