Cox model risk score to predict survival of intrahepatic cholangiocarcinoma after ultrasound-guided ablation

Abstract

Purpose: To explore factors associated with overall survival (OS) and progression-free survival (PFS) of intrahepatic cholangiocarcinoma (iCCA) after ultrasound-guided ablation and establish a model for survival risk evaluation.

Methods: Data from 54 patients with 86 iCCAs between August 2008 and October 2022 were retrospectively analyzed. Cox regression were used to analyze the effects of clinical features on OS and PFS. Based on the variables screened by multivariable analysis, a model was established to predict the survival of the patients. Time-dependent receiver operating characteristic (timeROC) curve was constructed to evaluate the performance of this model. The model was further verified by bootstrap validation. The clinical usefulness of the model was evaluated by the decision curve analysis (DCA).

Results: During follow up, 39 patients died and 49 patients developed recurrence. Pre-ablation CA199 level > 140 U/ml was the only independent predictor of poor PFS. Age > 70 years, early recurrence, maximal diameter of tumor size > 1.5 cm and pre-ablation CA199 level > 140 U/ml were significantly associated with poor OS. Then a model was established based on the above four variables. The areas under the timeROC curve (AUC) for 1-year, 2-year, 3-year, 5-year were 0.767, 0.854, 0.791 and 0.848, respectively. After bootstrapping for 1000 repetitions, the AUCs were similar to the initial model. DCA also demonstrated that the model had good positive net benefits.

Conclusion: The established model in this study could predict the survival outcomes of the patients with iCCA after thermal ablation, but further research was needed to validate the results.

Keywords: Intrahepatic cholangiocarcinoma; Overall survival; Risk regression model; Thermal ablation; Ultrasound.