Assessment of the Benefit of Surgical Treatment for Patients with Hepatocellular Carcinoma with Extrahepatic Metastases: A Nomogram for a Propensity Score Matching Study

Background: Most patients with extrahepatic metastases (EHM) from hepatocellular carcinoma (HCC) die from developing the primary tumor within the liver, not from EHM. Although surgery for primary tumors is not recommended in guidelines, some studies suggest that surgical treatment might prolong patient survival. Objectives: This study aimed to develop and validate an easy-to-use nomogram for preoperative assessment by physicians of patients with advanced extrahepatic metastatic hepatocellular carcinoma (HCC-EHM), factors associated with surgical treatment, and probability of benefit. Methods: By searching the SEER database of HCC patients with EHM by propensity score matching (PSM), 912 patients were finally included in the study. The patients in the surgery group were randomly assigned to the training and validation groups (7:3), and a nomogram was constructed to predict whether patients in the surgery group could benefit from receiving surgical treatment at the primary site and to validate the accuracy of the model and the overall survival of the surgery patients at 1, 3, and 5 years. Results: Several factors related to the grade, T staging, NM staging, tumor size, primary site surgery, alpha-fetoprotein (AFP), chemotherapy, and fibrosis score were finally included (P < 0.05). The area under the receiver operating characteristic curve (AUROC/area under the curve (AUC)) was 0.738 and 0.769 for the training and validation groups, respectively. The 1-, 3-, and 5-year survival rates were 0.725, 0.720, and 0.716, respectively. Conclusions: Based on the results, a nomogram can individually predict patients suitable for surgery and provide a reference for clinical decision-making.