Purpose: To describe the global landscape of clinical research into interventions for gastroesophageal cancers (GECs), with examination of trial characteristics, geographic distribution of trial sites, and factors associated with trial termination.
Methods: We queried ClinicalTrials.gov to identify all completed or terminated phase III interventional studies investigating GECs (esophageal squamous cell carcinoma [ESCC], esophageal adenocarcinoma [EAC], gastroesophageal junctional [GEJ], and gastric adenocarcinoma). Data on all reported trial characteristics were extracted. Pearson's chi-square and Fisher's exact tests were used to compare differences in completed and terminated trials. Multivariate logistic regression evaluated predictors of termination.
Results: A total of 179 trials were identified; of these, 90% were therapeutic. Most included sites in Asia (61%) and Europe (32%); few included sites in Africa (4%). Thirty percent included sites in low- and middle-income countries (LMICs). Most (70%) focused on gastric or GEJ adenocarcinoma, 13% on EAC and ESCC, and 9% on ESCC alone. Sixteen percent (n = 29) of trials terminated prematurely. In multivariate analysis, study site number, location of recruitment sites, and patient population emerged as predictors of termination. Trials recruiting from US-based sites were more likely to terminate (odds ratio [OR], 7.22 [95% CI, 1.59 to 32.69]). Trials conducted exclusively in LMICs were less likely to terminate (OR, 0.04 [95% CI, 0.01 to 0.59] v conducted in high-income countries [HICs] alone). Studies on ESCC were more likely to terminate (OR, 17.74 [95% CI, 1.49 to 210.69]).
Conclusion: Although 80% of GECs occur in LMICs, trial activity disproportionately occurs in HICs. Few trials focus on EAC/ESCC despite being highly fatal, highlighting an unmet need. Overall, this study highlights (1) a missed opportunity to recruit patients from high-incidence regions globally; and (2) a pressing need for increasing funding, infrastructure, and support for GEC trials in LMICs.