Survival trends of soft tissue sarcomas and gastrointestinal stromal tumors from 1995 to 2019: A SEER database analysis.

Abstract

e23528 Background: In the last 25 years, new therapies have been developed for gastrointestinal stromal tumors (GISTs), while treatments for many soft tissue sarcomas (STSs) have remained relatively stagnant with 90% of phase I/II trials focusing on repurposing existing drugs. This study compares survival changes over time in patients with STSs and GISTs. Methods: Data from the Surveillance, Epidemiology, and End Results (SEER)-9 registry were analyzed for patients aged 20+ diagnosed with GISTs and STSs from 1995 to 2019. Patients were categorized into time periods: 1995-2004, 2005-2014, 2015-2019. The primary outcomes were the 5-year overall survival (OS) difference between GISTs and STSs and survival variations across the periods. Survival was calculated using the Kaplan–Meier method, and differences were assessed with log-rank tests. Results: 26,633 STS and 3,818 GIST patients were identified. The 5-year OS rate was 53.0% (95% CI: 52.4-53.7) for STSs and 68.7% (95% CI: 67.1-70.3) for GISTs (p < 0.001), with a respective median OS of 72 (95% CI: 69-75) and 121 (95% CI: 113-128) months. For STS, the 5-year OS rate was 53.3% (95% CI: 52.3-54.4), 52.8% (95% CI: 51.9-53.8), and 54.2% (95% CI: 52.2-56.3) (p = 0.66) for groups 1995-2004, 2005-2014, and 2015-2019, respectively. For GIST, the 5-year OS rate was 60.7% (95% CI: 57.3-64.2), 70.6% (95% CI: 68.5-72.7), and 71.0% (64.5-78.3) (p < 0.001). In the locoregional setting (L), the GIST median 5-year OS was 70.5% (95% CI: 66.9-74.3), 78.1% (95% CI: 75.9-80.3), and 79.0% (95% CI: 71.4-87.4) (p < 0.001). In the metastatic setting (M) for GIST, the 5-year OS rate was 30.7% (95% CI: 24.8-37.9), 45.7% (95% CI: 41.1-50.7), and 46.3% (95% CI: 35.8-59.8) (p < 0.001). However, no significant difference was seen for STSs in either setting (L1995-2004 61.6% 95% CI: 60.5–62.8, M1995-2004 11.2, 95% CI: 9.7–12.9, L2005-2014 61.5%, 95% CI: 60.5–62.5, M2005-2014 10.2, 95% CI: 8.9–11.7, L2015-2019 63.4%, 95% CI: 61.2–65.7, M2015-2019 12.1, 95% CI: 9.4–15.6, p(L) = 0.71 and p(M) = 0.74). Conclusions: While GIST survival rates significantly improved, those for other STSs remain unchanged, highlighting an urgent need for novel STS therapies. [Table: see text]