A Scoring System for Risk Stratification in Intrahepatic Cholangiocarcinoma after Immunotherapy

Purpose To identify clinical and radiologic factors associated with outcomes and develop a prognostic scoring system for patients with proficient mismatch repair or microsatellite stable intrahepatic cholangiocarcinoma (iCCA) undergoing preoperative immunotherapy. Materials and Methods This retrospective study included patients who underwent MRI and immunotherapy before surgery at a tertiary referral academic center between October 2019 and May 2023. Least absolute shrinkage and selection operator regression was performed to identify relevant clinical and radiologic features associated with recurrence-free survival (RFS), followed by multivariable Cox proportional hazards analysis to construct a nomogram incorporating all independent prognostic factors. Performance of the nomogram model was assessed using the concordance index, and RFS was analyzed using Kaplan-Meier curves and log-rank testing. Results This study included 77 patients (45 male patients) with a median age of 60 years (IQR: 51-66 years). Least absolute shrinkage and selection operator regression identified 14 potential factors, and multivariable Cox analysis determined seven independent prognostic factors: male sex (hazard ratio [HR]: 2.1, P = .04), history of hepatitis B (HR: 2.3, P = .04), microvascular invasion (HR: 3.7, P = .02), preoperative carbohydrate antigen 19-9 levels (HR: 1.1, P = .04), number of tumors (HR: 1.1, P = .03), tumor size (HR: 1.2, P = .006), and lobulated or irregular morphology (HR: 4.4, P = .004). The nomogram incorporating these factors predicted RFS with a concordance index of 0.72 (95% CI: 0.65, 0.80). Nomogram-based risk stratification revealed significant differences in RFS between groups (P < .001), with a median RFS of 42 months in the low-risk group and 10 months in the high-risk group. Conclusion The proposed prognostic scoring system provides a valuable tool for evaluating prognosis in patients with proficient mismatch repair or microsatellite stable iCCA undergoing preoperative immunotherapy, which can aid clinical decision-making. Keywords: MR Imaging, Abdomen/GI, Outcomes Analysis Supplemental material is available for this article. © RSNA, 2025.