Development and validation of prognostic nomograms for intrahepatic cholangiocarcinoma with concomitant hepatolithiasis after radical resection.

BACKGROUND: Patients with intrahepatic cholangiocarcinoma (ICC) and concomitant hepatolithiasis constitute a distinct clinical subgroup, but prognostic models for this population are scarce. We therefore developed and validated nomograms to predict postoperative recurrence-free survival (RFS) and overall survival (OS). METHODS: A total of 335 patients with ICC and concomitant hepatolithiasis who underwent radical resection were retrospectively enrolled. The cohort was randomly divided into a training cohort (n=161) and an internal validation cohort (n=69) from 230 patients, while 105 patients from an external institution constituted an independent validation cohort. Multivariable Cox regression analysis identified independent prognostic factors for RFS and OS. Nomograms based on these factors were subsequently constructed and validated using calibration curves, time-dependent receiver operating characteristic (ROC) curves, and C-index. RESULTS: Vascular invasion, tumor number, lymph node metastasis, tumor size, carcinoembryonic antigen (CEA), microfibrillar-associated protein 4 (MFAP4), and albumin-bilirubin (ALBI) grade were independent predictors of RFS, while vascular invasion, tumor number, lymph node metastasis, carbohydrate antigen 19-9 (CA19-9), CEA, MFAP4, and ALBI grade were independently associated with OS. The resulting nomograms demonstrated good calibration and discrimination. In the training cohort, the C-index for RFS and OS were 0.840 and 0.852, respectively; these values were 0.823 and 0.832 in the internal validation cohort, and 0.862 and 0.870 in the external validation cohort. CONCLUSIONS: The developed nomograms accurately predicted postoperative RFS and OS in patients with ICC and concomitant hepatolithiasis, thereby supporting individualized risk stratification and postoperative management.