Treatment patterns and long-term clinical outcomes in Chinese patients with nonmetastatic gastric cancer: Results from the non-interventional EVIDENCE registry study.

Abstract

307 Background: Although gastric cancer (GC) is a leading cause of cancer-related death in China, important questions about optimal management remain unanswered. The EVIDENCE registry study evaluated data from patients with GC in China to assess the pattern of treatments and long-term clinical outcomes. Methods: Five cohorts of patients with different HER2 and metastatic (m) status were evaluated from April 2013 to June 2018 in this prospective, multicenter, non-interventional, real-world study. Data from patients with operable non-mGC are reported: Cohort III (HER2+) and Cohort V (HER2−). Outcome measures included overall survival (OS), event-free survival (EFS), and disease-free survival (DFS). Results: Cohorts III/V included 758 patients (Cohort III, 271; Cohort V, 487); 75.5% were male and the mean age was 58.8 years. The majority of Cohort III/V patients (538/758; 71.0%) received only adjuvant treatment, with 215/758 (28.4%) receiving S1+oxaliplatin. Neoadjuvant or adjuvant trastuzumab was administered to 43/758 patients (Cohort III, 42; Cohort V, 1). Radiation during neoadjuvant or adjuvant treatment was administered to 23/758 (3.0%) patients. The median duration of follow-up was 515 days, during which 72 (9.5%) patients died due to progressive disease. OS rates (95% CI) for Cohorts III and V were 94% (89–96) and 95% (92–97) at 1 year, and 76% (67–83) and 70% (64–75) at 3 years, respectively. Respective EFS rates were 82% (76–87) and 86% (83–89) at 1 year, and 62% (53–70) and 57% (51–63) at 3 years; and respective DFS rates were 88% (82–93) and 86% (81–89) at 1 year and 69% (58–78) and 62% (55–68) at 3 years. Multivariate analysis indicated that the primary tumor site (p = 0.004) and overall cancer stage (p < 0.001) were associated with DFS. Regarding the primary tumor site, there was a trend towards better DFS for antrum tumors (hazard ratio 0.59; 95% CI 0.32–1.07) when evaluated against gastroesophageal junction tumors. Conclusions: This longitudinal analysis of clinicopathologic characteristics and outcomes of Chinese patients with non-mGC will provide critical information that will help to inform disease management. Clinical trial information: NCT01839500.