Value of staging information provided by linear-array endoscopic ultrasound for therapeutic response and prognosis prediction in gastric lymphoma.

Abstract

Currently, positron emission tomography/computed tomography (PET/CT)-based Ann Arbor and Lugano staging systems are widely applied for gastric lymphoma, which majorly focused on the extent of systemic invasion, but there is insufficient assessment in extent of gastric wall invasion. Thus, we aimed to assess the value of linear-array EUS in therapeutic response and prognosis prediction, and provide an endoscopic ultrasound (EUS)-based staging system for gastric lymphoma. Between January 2012 and October 2019, 191 patients with histologically confirmed gastric lymphoma were included. We analyzed patients' clinicopathologic data, white-light appearance, EUS staging, tumor extension, and therapeutic regime to identify the predictors for complete remission (CR) and progression-free survival (PFS). With a median follow-up period of 547days, 136 patients achieved CR. Multivariate regression analysis identified EUS T stage three CR predictors, including T stage (T2-T4 vs. T1, OR=0.271, 95% confidence interval (CI)=0.108-0.683, P=0.0085) was the independent predictor. The Ki67 index, lesion surface, EUS stage, tumor extension, and regime predicted PFS, but tumor extension was the only independent predictor (local vs. system, OR=6.005, 95%CI=2.365-15.236, P<0.001). The concordance index (C-index) was higher for CR rate in the EUS-based staging [0.673; 95% CI=0.628-0.718] than Lugano staging [0.663; 95% CI 0.616-0.710], and for PFS in the EUS-based staging [0.694; 95% CI 0.586-0.802] than Lugano staging [0.684; 95% CI 0.564-0.804]. An EUS-based staging system is suitable for CR and PFS prediction in gastric lymphoma, with highly informative assessment in extent of gastric wall invasion.