No significant relationship exists between tumor size and prognosis in distant metastatic hepatocellular carcinoma: a propensity score matching analysis based on SEER database

BACKGROUND: Previous studies have shown that tumor size has an impact on the prognosis of hepatocellular carcinoma (HCC). Whether tumor size is related to the prognosis of distant metastatic HCC is unclear. The purpose of this study was to investigate the effect of tumor size on the prognosis of distant metastatic HCC. METHODS: Data on patients with HCC were collected from the (SEER) database of surveillance, epidemiology and final results. Propensity score matching (PSM) was used to reduce confounding factors and comprehensively evaluate the clinicopathological features and prognosis of distant metastatic HCC. RESULTS: There were 189 patients with distant metastatic HCC whose tumor size was ≤ 50 mm and 615 patients with a tumor size > 50 mm. The tumor sizes of distant metastatic HCC patients were associated with race, grade, surgical treatment, N and AFP. The Kaplan–Meier analysis showed that the mortality rate of patients with a tumor size > 50 mm was higher than that of patients with a tumor size ≤ 50 mm (p = 0.00062). However, there were no significant differences in mortality rates after adjusting for confounding variables by using propensity score matching (p = 0.23). CONCLUSION: This propensity score matching study provides the best data in support of the following assertions: tumor size is not an independent prognostic factor for distant metastatic HCC. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12876-022-02355-1.