Incidence and Predictors of Synchronous Liver Metastases in Patients with Gastrointestinal Stromal Tumors (GISTs)

Background: The liver is the most common metastatic site in patients with gastrointestinal stromal tumors (GISTs). The purpose of this study is to identify the incidence and predictive factors associated with synchronous liver metastases among patients with GISTs.

Methods: A retrospective review of the Surveillance Epidemiology and End Results (SEER) database was performed.

Results: Overall, 2757 patients were identified, of which 276 (10%) had synchronous liver metastases. The two-year survival of patients with synchronous liver metastases was 31.9% overall and 37.1% after undergoing surgery with curative intent. Primary tumor size >5 cm (5-10 cm: OR 2.97, 95% CI: 1.03-8.55, p = 0.044, >10 cm: OR 5.59, 95% CI: 1.95-16.07, p = 0.001), presence of nodal metastases (OR 4.09, 95% CI: 2.01-8.33, p < 0.001) and mitotic count >5/50 HPF (OR 1.58, 95% CI: 1.01-2.47, p = 0.044) were associated with the presence of liver metastases.

Conclusions: One out of ten patients with GISTs presents with hepatic metastases. Primary tumor size >5 cm, presence of nodal metastases and mitotic count >5/50 HPF are associated with a higher risk of synchronous hepatic metastases.