Prognostic impact of portal area inflammation on intrahepatic cholangiocarcinoma patients without lymph node metastasis

Background: Inflammation in the peritumoral normal tissues has impact on tumors. This study investigated the prognostic impact of portal area inflammation (PAI) on postoperative tumor recurrence and overall survival (OS) in patients undergoing resection for intrahepatic cholangiocarcinoma (ICC) without lymph node metastasis (LNM).Methods: Two hundred and ninety-seven patients who had undergone curative-intent resection at the Eastern Hepatobiliary Surgery Hospital, Shanghai, between 2011 and 2015 were selected. All patients were histologically diagnosed with ICC and had no LNM. PAI was defined by experienced pathologists based on standard pathological evaluations. Patients were divided into two groups according to the presence or absence of PAI. Further survival analysis was performed on PAI-related endpoints, OS, and recurrence-free survival (RFS), using Kaplan-Meier analysis and multivariate regression.Results: Among the 297 patients included in the study, the PAI incidence was 43.1% (128 patients). OS and RFS were worse in patients with PAI than in those without PAI (median OS, 21.87 months with PAI versus 33.37 months without PAI, P<0.001; median RFS, 12.33 months with PAI versus 21.60 months without PAI, P<0.001). Multivariate analysis revealed that PAI was an independent prognostic factor for both OS [hazard ratio (HR) 1.60; 95% confidence interval (CI): 1.18-2.17, P=0.003] and RFS (HR 1.40; 95% CI: 1.06-1.85, Conclusions: Consequently, PAI is a strong independent predictor of tumor recurrence and OS after curative-intent resection in patients with ICC without LNM. The impact of PAI on the postoperative prognosis of ICC patients without LNM is non-negligible. It is strongly recommended to pay attention to the inflammatory status of the portal area in ICC patients and increase the frequency of postoperative followup to improve the prognosis of ICC patients after curative resection.