Objective To investigate the prognostic value of hepatitis B virus surface antigen (HBsAg) in patients with colorectal cancer liver metastases (CRLM) after hepatectomy and establish a prediction model.

Methods In this retrospective study, the clinical data of 178 patients with CRLM who underwent hepatectomy at the Guangxi Medical University Cancer Hospital from January 2013 to December 2023 were collected and divided into HBsAg-negative group (n=160) and HBsAg-positive group (n=18). Univariate and multivariate Cox regression analyses were used to screen independent risk factors affecting progress-free survival (PFS) and overall survival (OS) in CRLM patients, and the nomogram model was constructed. The performance of nomogram was evaluated by the receiver operating characteristic (ROC) curve, calibration curves and decision curve analysis (DCA). Based on the nomogram, the risk scores of each patient were calculated. X-tile software was used to divide the patients into the low-risk group and the high-risk group. Kaplan-Meier curve was plotted, and log-rank test was performed to compare the survival differences between the two groups.

Results The risk of extrahepatic metastasis after hepatectomy was higher in the HBsAg-positive group than that in the HBsAg-negative group (P < 0.05), and there was no significant relationship between HBsAg positivity and the development of postoperative intrahepatic metastasis (P > 0.05). The median PFS in the HBsAg-negative group was longer than that in the HBsAg-positive group (P < 0.05), but there was no significant difference in the median OS between the two groups (P > 0.05). Cox regression analysis results showed that HBsAg positivity was an independent risk factor for PFS in CRLM patients after hepatectomy (HR=1.793, 95% CI: 1.041-3.088, P=0.035) and did not affect OS (P > 0.05). ROC curve, calibration curve and DCA all suggested that the nomogram model constructed based on HBsAg for predicting PFS indicated good discriminative ability, calibration ability and clinical practicability. The log-rank test showed that the PFS of the low-risk group was longer than that of the high-risk group (P < 0.0001).

Conclusion HBsAg positivity is an independent risk factor for PFS in CRLM patients after hepatectomy and does not affect OS. RLM patients with HBsAg positivity have a higher risk of extrahepatic metastases after hepatectomy, and there is no significant relationship between HBsAg positivity and the development of postoperative intrahepatic metastasis. The nomogram model constructed based on HBsAg can assist in predicting PFS in patients with CRLM after hepatectomy.