Localized GIST in Hispanic population in North and South America.

Abstract

e23513 Background: Most studies of gastrointestinal stromal tumors (GIST) focus upon patients in a single country. However, differences in patient presentation, treatment, and outcomes may differ between nations. We sought to compare Hispanic patients with localized GIST treated in North and South America. Methods: We performed a retrospective analysis including all Hispanic GIST patients treated at 3 tertiary referral centers in the United States (US), Mexico (MX) and Argentina (AR), as well as those enrolled by 2 patient advocacy groups in US and MX from 2000-2022. Demographic, clinicopathologic and survival data were collected and compared using Pearson’s chi-square or one-way ANOVA test. Disease-specific survival (DSS) was calculated using the Kaplan-Meier method and compared using the log-rank test. Results: Overall, 1,504 Hispanic patients (54.5% female) were analyzed. Median age at diagnosis was significantly lower in US (48 y) than MX/AR (55/57 y, p = 0.001). Presentation stage varied by country. Localized presentation was more frequent in US/MX (77%/88%) than AR (60%, p = 0.001). In 1,208 patients (80.4%) with localized disease, 97.9% underwent surgical resection. Rates of adjuvant imatinib treatment varied from 82.4%/77.0% in US/MX to 35.6% in AR (p < 0.001). Median duration of adjuvant therapy was longer in US (29 mos; range: 16-48) than MX (12 mos; range: 4-36, p < 0.001). With a median follow up of 44 mos (range: 24-78) for patients presenting with localized GIST, the estimated median DSS was 136 mos (95% CI 104-167), being significantly longer in US (267 mos, 95% CI 95-439, p = 0.02). Conclusions: While most studies of disparities focus on differences between races/ethnicities in a single country, we found that disparities also exist within similar ethnic groups across nations. Underappreciated sociopolitical determinants of health likely lead to differences in presentation, management, and long-term outcomes of Hispanic GIST patients in the Americas. Prospective cooperative studies are needed to better define barriers to care in order to improve patient outcomes in Hispanic GIST patients. [Table: see text]