Construction and Validation of a Nomogram for The Prediction of Overall Survival in Intrahepatic Cholangiocarcinoma

Objective: This study aimed to establishand validates a nomogram to predict the overall survival (OS) of patients with intrahepatic cholangiocarcinoma (ICC).Patients and methods: The ICC patients were collected from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Then, the independent prognosis-related factors were obtained from the training set using the Cox regression model for the establishment of a nomogram.Results: We identified 3675 eligible patients with a median survival time of 9 months (0–153 months). According to multivariate analysis, age, sex, marital status, grade, T stage, N stage, M stage, surgery, chemotherapy and radiotherapy were identified as the factors to independently predictthe prognosis for ICC (all P<0.05). Thereafter, the above factors were incorporated for the construction of a nomogram. In comparison with the AJCC 8th TNM classification system and the SEER summary stage system, our constructed nomogram showed higher ability in discrimination, as revealed by the C-index (all P<0.001).Besides, the internal as well as external calibration curve analysis demonstrated that the predicted results were highly consistent with the actual ones. On the other hand, our nomogram outperformed the AJCC 8th TNM classification system and the SEER summary stage system in predicting the 3- and 5-year OS, as suggested by time-independent area under the curve (tAUC) values.Conclusion: Our constructed nomogram performs well, indicating its potential as an efficient approach to evaluate the prognosis of ICC patients.