Impact of Trinal Histological Glandular Differentiation Grade on the Prognosis of Patients with Intrahepatic Cholangiocarcinoma: a Multicenter Retrospective Study

Introduction It is unclear whether the histological glandular differentiation (HGD) score that evaluates the tumor grade of two dominant components is prognostic for survival in patients with intrahepatic cholangiocarcinoma (ICC). Method We retrospectively analyzed the clinical and histopathologic data of 235 consecutive patients with histologically confirmed ICC following hepatectomy at 5 university hospitals in the Kansai region of Japan. Results Survival was statistically significantly stratified by trinal HGD grade ( p < 0.05). Median disease-free survival (DFS) of patients with high HGD grade was significantly shorter compared with moderate HGD grade (13.0 vs 31.2 months, respectively; p = 0.004). By Cox proportional hazards regression analysis, HGD grade had the fifth-highest hazard ratio (HR = 1.77, p = 0.002) for DFS after vascular and/or biliary invasion, extrahepatic invasion, lymph node metastasis and multiple tumors. Multivariate logistic regression analysis revealed four predictors of early recurrence after hepatectomy (lymph node metastasis: odds ratio [OR] = 3.74, p = 0.001; tumor size > 50 mm: OR = 2.80, p = 0.002; HGD grade, high: OR = 2.11, p = 0.012; and vascular or biliary tract invasion: OR = 2.11, p = 0.048). Conclusion Trinal HGD grade had a significant prognostic impact on the survival of patients with ICC after radical hepatectomy.