Development and Validation of Prognostic Nomogram for Young Patients with Hepatocellular Carcinoma (HCC): A Study Based on SEER Database

This study was to establish nomogram models for prognostic evaluation of hepatocellular carcinoma (HCC) in both overall survival (OS) and cancer-specific survival (CSS). Firstly, retrospective collected clinical data from 650 patients diagnosed with HCC in the Monitoring SEER database from 2004 to 2018 were divided into validation sets and training sets in a 1:1 ratio. Then using the cox proportional risk regression model, the survival rate was calculated using the Kaplan-Meier method and the survival curve was plotted. The consistency index (C-index) and calibration graph were used to verify the predictive performance of the nomogram. A total of 650 HCCs were selected during this process. Age, race, tumor size, T stage, N stage, and M stage were independent risk factors affecting the prognosis of HCC patients, and the OS nomogram was constructed based on the above independent risk factors, the CSS nomogram was constructed based on tumor size and SEER stage. In the training set, the C-index of the OS nomogram is 0.718 (95% CI is 0.691-0.745), and the C-index of the CSS nomogram is 0.674 (95% CI 0.647-0.701). In external validation, the C index of the OS nomogram is 0.688 (95% CI is 0.661-0.715), and the C index of the CSS nomogram is 0.655 (95% CI 0.636-0.694). Both OS and CSS nomogram models showed high-quality calibration plots. The nomogram models provided an insightful and applicable tool to evaluate the prognosis of HCC both in OS and CSS.