A clinical model to predict the risk of distant metastasis in intrahepatic cholangiocarcinoma and to explore the benefits of radiotherapy and chemotherapy

Objective: To develop a clinical prediction model for the risk of distant metastasis in patients with intrahepatic cholangiocarcinoma, to assess the risk of distant metastasis and prognosis of patients, and to explore the efficacy of radiotherapy and chemotherapy in people with different risks of distant metastasis. Method: Clinicopathological data of 15,497 patients diagnosed with intrahepatic cholangiocarcinoma from January 2000 to December 2018were extracted from the Surveillance, Epidemiology, and End Results (SEER) database, and all eligible patients were randomly divided into a training cohort and a validation cohort in a 7:3 ratio. Univariate and multivariate logistic regression analyses were performed on the training cohort to identify independent factors for distant metastasis. A prediction model for distant metastasis in patients with intrahepatic ductal carcinoma was constructed based on the independent risk factors for distant metastasis. Receiver Operating Characteristic (ROC) and calibration curves were used to assess the predictive accuracy of the model, and Decision Curve Analysis (DCA) was used to evaluate the clinical utility of the column line graphs.Tumor distant metastasis risk stratification and subgroup survival analysis were performed according to the model, and the benefits of radiotherapy and chemotherapy were explored with the help of the model. Result: Multivariable logistic analysis showed that age, T-stage, N-stage, degree of differentiation, and tumor size were independent risk factors for distant metastasis. The area under the ROC curve (AUC value) was 0.733 (CI95%: 0.713-0.753) and 0.750 (CI95%:0.721-0.780) for the training and validation sets, respectively, and the calibration curves indicated good agreement between predicted and actual values, and the decision curves showed good clinical utility of the model.Subgroup survival analysis suggested that the prognosis is poor in the intermediate and high risk groups, and that radiotherapy and chemotherapy canimprove the prognosis in these groups, with no benefit for the low risk groups. Conclusion: The prediction model of distant metastasis in patients with intrahepatic cholangiocarcinoma based on the SEER database has good prediction accuracy, which helps physicians to assess the risk of distant metastasis and prognosis of patients, thus providing a reference for individualized clinical treatment decisions for patients. Chemotherapy and radiotherapy can significantly improve the survival prognosis of patients with intermediate and high risk of distant metastasis.