Utilization and survival outcomes of neoadjuvant chemotherapy for early-stage gastric cancer.

Abstract

Given increased utilization of neoadjuvant therapy (NAT) for gastric adenocarcinoma, practice patterns deviating from standard of care (upfront resection) remain unknown. We sought to identify factors associated with NAT use and survival outcomes among early-stage gastric cancers. The National Cancer Database identified patients with early-stage (T1N0M0) gastric cancer (2010-2020). Multivariable logistic regression assessed characteristics associated with NAT utilization compared to upfront surgery. After 1:1 propensity score matching, Kaplan-Meier methods and Cox regression assessed overall survival (OS). Of 6452 patients with early-stage gastric cancer, 626 (9.7%) received NAT. Patients who received NAT were more likely treated at community hospitals, had moderate to poorly differentiated disease, and tumors located in the cardia (all p < 0.05). After propensity score matching, 1,248 patients remained. Median OS for NAT was 37.1 months (IQR 20.2-64.0) versus 45.6 months (IQR 22.5-72.8) for resection (p < 0.001). Treatment with NAT remained independently predictive of worse OS on Cox regression (hazard ratio 1.19; 95% confidence interval 1.05-1.34). Although patients who received NAT had more aggressive prognostic features, NAT was associated with worse OS despite accounting for this selection bias. These results highlight the importance of adhering to guidelines, regardless of differing disease characteristics, which has significant implications on outcomes.