Multicentric evaluation of a clinical and prognostic scoring system predictive of survival after resection of intrahepatic cholangiocarcinomas

Objective: To develop a clinical and prognostic scoring system predictive of survival after resection of intrahepatic cholangiocarcinomas (ICC). Patients: Two hundred and one consecutive ICC patients (83 from Essen, Germany, 54 from New York, USA and 64 from Chiba, Japan). The scoring systems were developed utilizing the data set from Essen University and then applied to the data sets from Mount Sinai Medical Center and Chiba University for validation. Eighteen potential prognostic factors were evaluated. Statistical analysis included multivariable regression analyses with the Cox proportional hazard model, power analysis, internal validation with structural equation modelling bootstrapping and external validation. The prognostic scoring model was based mainly in pathological and demographical variables, whereas the clinical scoring model was based mainly in radiological and demographical variables. Results: Gender (P=0.0086), UICC stage (P=0.0140) and R-class (P=0.0016) were predictive of survival for the prognostic scoring model, while gender (P=0.0023), CA 19-9 levels (P=0.0153) and macrovascular invasion (P=0.0067) were predictive of survival for the clinical scoring model. Prognostic points were assigned as follows: female:male=1:2 points, UICC (I-II):UICC (III-IV)=1:2 points and R0:R1=1:2 points. Clinical points were allocated as follows: female:male=1:2 points, CA 19-9 (<100 U/ml):CA 19-9 (≥100 U/ml)=1:2 points and no macrovascular invasion:macrovascular invasion=1:2 points. Prognostic groups with 3-4, 5 and 6 points (P=0.000001) and clinical groups with 3-4 and 5-6 points (P=0.0103) achieved statistically significant difference. Conclusions: We propose a clinical and prognostic scoring system predictive of long-term survival after surgical resections for ICC.