The benefit of surgery during systematic therapy for gastrointestinal stromal tumor liver metastasis: a SEER-based retrospective study

Background: The liver is the most common site of gastrointestinal stromal tumor (GIST) metastasis. Most patients who develop metastases gradually develop multiline drug resistance during long-term systematic treatment. We aimed to evaluate the benefit of surgery during the systematic treatment of GIST liver metastases. Methods: Data on GISTs with liver metastasis were retrieved from the Surveillance, Epidemiology, and End Results database. This study included 607 patients, of whom 380 patients were treated with chemotherapy alone (Chemo group) and 227 patients underwent surgery in addition to chemotherapy (Chemo&Surg group). The primary outcomes were cancer-specific survival (CSS) and overall survival (OS). Propensity score matching (PSM) was performed to balance the baseline factors. Results: According to the multivariate analysis, surgery benefitted both CSS and OS (P < 0.001). After PSM, surgical resection still showed significant benefits in terms of both CSS and OS (P < 0.001). Surgery combined with chemotherapy increased the median CSS by at least 63 months and the median OS by at least 76 months. Subgroup analysis of the Chemo&Surg group revealed that the timing of surgery was not an independent influencing factor for either CSS or OS. Conclusions: We found that performing additional surgery, in addition to systematic therapy, for GIST liver metastasis resulted in improved CSS and OS. These benefits were not affected by the timing of surgery during systemic treatment.