Abstract: Objective To explore prognostic factors of patients with distant metastatic hepatocellular carcinoma (DMHCC) and construct a survival prognosis nomogram to predict cancer-specific survival (CSS) for DMHCC patients.Methods A total of 619 patients from the SEER database (2000-2018) were included after strict inclusion and exclusion criteria.They were randomly divided into two groups at a ratio of 7〖DK〗∶3,among which there were 433 cases in the training set and 186 cases in the validation set.Cox regression analysis was used to screen out the independent risk factors affecting the prognosis of patients with DMHCC,and a nomogram was constructed.The predictive accuracy of the nomogram was determined by concordance index (C-index),receiver operating characteristic(ROC) and calibration curves.The clinical net benefit of the nomogram was assessed using decision curve analysis (DCA).Kaplan-Meier survival curves and Log-rank tests were performed for examining survival differences between high and low-risk groups.Results Multivariate Cox regression analysis revealed that tumor size,degree of tumor differentiation,T stage,whether or not surgery,chemotherapy or radiotherapy were independent risk factors influencing the prognosis of DMHCC patients.The nomogram,based on these factors,demonstrated good predictive performance in the training set with a C-index of 0.720 (95%CI:0.693-0.747),and area under the ROC curve at1,2,and3 years was 0.790,0.778,and 0.795,respectively.In the validation set,the C-index was 0.673 (95%CI:0.626-0.720),and area under the ROC curve at 1,2,and 3 years was 0.741,0.782,and 0.824,respectively.Risk stratification was performed with the nomogram.Kaplan-Meier survival curve indicated that for both training and validation sets,low-risk group had a significantly better prognosis than high-risk group.Conclusion This prediction model exhibits good predictive efficacy,providing valuable support for clinical decision-making and personalized treatment strategies in DMHCC patients.

Key words: hepatocellular carcinoma, distant metastasis, prognosis, nomogram