Metastases of soft tissue sarcoma to the liver: A Historical Cohort Study from a Hospital‐based Cancer Registry

BACKGROUND: Hepatic metastasis of soft tissue sarcoma is rare compared to lung metastasis, and the literature is scarce. We examined the risk of hepatic metastasis according to the site of occurrence and histological type. METHODS: From a Hospital‐based Cancer Registry, 658 patients registered between 2007 and 2017 with soft tissue sarcomas were evaluated. The exclusion criteria were gastrointestinal stromal tumors, tumors of unknown origin, and follow‐up periods of less than 1 month. SPSS 25 was used for statistical analysis. RESULTS: The risk of hepatic metastasis was significantly higher in the retroperitoneum (HR, 5.981; 95% CI, 2.793‐12.808) and leiomyosarcoma (HR, 4.303; 95% CI, 1.782‐10.390). Multivariate analysis showed that the risk of hepatic metastasis as first distant metastasis was high in leiomyosarcoma (HR, 4.546; 95% CI, 2.275‐9.086) and retroperitoneal onset (HR, 4.588; 95% CI, 2.280‐9.231). The 2‐year survival rate after hepatic metastasis was 21.7%. CONCLUSIONS: The onset of hepatic metastasis indicates a poor prognosis. However, hepatic metastasis from retroperitoneal sarcoma and leiomyosarcoma may be the first distant metastasis in some cases. For retroperitoneal sarcoma and leiomyosarcoma, additional screening for hepatic metastasis such as contrast CT should be considered during staging and follow‐up after treatment.