Construction and validation of a novel prognostic model for postoperative patients with stage I intrahepatic cholangiocarcinoma: a population-based study.

PURPOSE: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary malignant tumor of the liver. Surgery is routinely recommended for stage I ICC patients. The independent prognostic factors affecting stage I ICC patients after surgery remain unclear. METHODS: Altogether, 349 ICC stage I patients undergoing curative operation from the Surveillance, Epidemiology, and End Results (SEER) database were registered from 2010 to 2021 in this research. Random assignment of these patients was carried out in a 7:3 proportion, forming a training cohort consisting of 245 and an internal validation cohort consisting of 104. Independent prognostic factors were recognized by univariate and multivariate analysis in the training cohort. Subsequently, the prognostic nomogram was constructed using independent prognostic factors in the training cohort, and the nomogram was validated internally and externally using data from the internal validation cohort and a cohort from Eastern Hepatobiliary Surgery Hospital, respectively. RESULTS: Multivariate analysis demonstrated that race, grade, tumor size, and lymph node removal had associations with overall survival (OS) in postoperative patients with stage I ICC in the training cohort (P < 0.05). Then the prognostic nomogram for these patients was constructed on the basis of the above variables. The C-indexes for internal and external validation of the nomogram were 0.65 and 0.63, respectively. In addition, the internally validated and externally validated 1-year, 3-year, and 5-year OS calibration curves exhibited a good fit, suggesting that the nomogram had good predictive power. CONCLUSION: The prognostic nomogram of postoperative patients diagnosed with stage I ICC performs well. This novel nomogram may help clinicians make individualized predictions of postsurgical outcomes for patients with stage I ICC and provide new perspectives for effectively assessing the value of surgery to the patient.