The impact of liver resection on survival outcomes of hepatocellular carcinoma patients with extrahepatic metastases: A propensity score matching study

BACKGROUND: The majority of hepatocellular carcinoma patients (HCCs) with extrahepatic metastases die of progressive intrahepatic tumor. There have been little data on the role of primary tumor resection (PTR) for HCCs with extrahepatic metastases but with resectable primary tumors. METHODS: A retrospective study was conducted on HCCs with extrahepatic metastases with resectable primary tumors who either underwent or did not undergo PTR in the SEER registry between 2004 and 2013. The overall and cancer‐specific survivals (OS and CSS) were assessed by the log‐rank test and the Cox proportional hazard regression model. A propensity score matching was conducted to minimize biases. Validation was performed in another cohort from the Sun Yat‐sen Memorial Hospital (SYSMH). RESULTS: Of the 529 HCCs with extrahepatic metastases with resectable primary tumors included into this study, 230 patients underwent PTR and 299 did not. The percentages of patients who underwent PTR increased from 38.6% in 2004 to 70.3% in 2013. In the propensity score‐matched patients, PTR was associated with improved OS (HR 0.310, P < 0.001) and CSS (HR 0.326, P <0.001). These improvements in survivals remained significant after sensitivity analyses using multiple imputation. In the validation cohort from the SYSMH (n = 131), PTR was also correlated with improved OS (HR 0.508, P = 0.002) and CSS (HR 0.568, P = 0.017). CONCLUSIONS: This study using propensity score matching and multiple imputation demonstrated that PTR had a favorable impact on the prognosis of HCCs with extrahepatic metastases with resectable primary tumors. Further prospective randomized trials are needed to confirm these findings.