Cbl-b predicts postoperative survival in patients with resectable pancreatic ductal adenocarcinoma

Casitas B-lineage lymphoma b (Cbl-b) is a ubiquitin-protein ligase and a signal transducing adaptor protein involved in immune regulation, and it may be involved in the development and progression of cancer. We investigated the association between Cbl-b expression and prognosis in patients with resectable pancreatic ductal adenocarcinoma (PDAC). The clinicopathological characteristics and survival data of 134 patients with surgery for PDAC between January 2009 and February 2012 were retrospectively evaluated, and Cbl-b expression was assayed by immunohistochemical staining. The association of Cbl-b expression with clinicopathological features and postoperative prognosis was analyzed. Cbl-b expression was strongly associated with the pathological primary tumor (pT) category (P = 0.005) and pathological TNM (pTNM) stage (P = 0.035), but not with other clinicopathological characteristics (all P > 0.05). In addition to current markers including pathological regional lymph nodes (pN) category, CA19-9, and histological differentiation, univariate and multivariate analysis found that Cbl-b was independently associated with overall survival (OS) of patients with resectable PDAC. Cbl-b was predictive of OS in a subgroup of patients with serum CA19-9 = 37 U/mL. Cbl-b expression combined with pN, histological differentiation, and CA19-9 level could be used as a novel clinical model predictive of OS for patients with resectable PDAC. In conclusion, Cbl-b in resectable PDAC was an independent predictor of adverse prognosis. Cbl-b expression together with pN, histological differentiation, and CA19-9 level might lead to improved risk stratification and prognosis for patients with resectable PDAC.