Ethnic Disparities in Demographic, Clinicopathologic, Biological Behaviors, and Prognosis of Gastric Cancer in Northwest China

Background: This retrospective study aimed to investigate ethnic disparities in demographic, clinicopathologic and biological behaviors of gastric cancer (GC) and established a novel nomogram for predicting overall survival (OS) of individual patients between two main ethnicities in a high GC-incidence area of China. Methods: There were 5,022 GC patients, including 3,987 Han (79.4%) and 987 Hui (14.4%) from Northwest China. All patient data were retrieved from 2009 to 2017. Median survival was estimated using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional hazards model and the rms package of R were used to assess the impact of covariates and to generate the nomogram prediction model, respectively. Findings: Similarly low 5-OS rates were shown in both the Hui and Han groups (23.8% vs 24.2%). Hui at stage T1, N0 or with tumour sizes below 5 cm had 2.144-fold, 1.426-fold or 1.305-fold increased risks of poor prognosis compared with Han ( P <0.05). Further, Hui had 1.265-, 1.364- and 1.401-fold increased risks of poor prognosis compared with Han when all patients had high expression of Ki67, EGFR, and VEGF, respectively ( P <0.05). Based on the data from the Cox model, the nomogram exhibited superior 3- and 5-year survival predictive ability to that of the 7 th AJCC TNM staging system. Interpretation: Ethnic disparities exist in the GC prognosis in Northwest China. Understanding the effects of ethnicity on GC will guide reasonable evaluations of prognosis and future interventions to equalize access to high-quality care for GC patients of different ethnicities in China. Funding Statement: This study was funded by grants from National Natural Science Foundation of China (No. 81760525, 81160249, and 81560485). Declaration of Interests: The authors declared no potential conflicts of interest. Ethics Approval Statement: The study was approved by the Ethical Committee of Ningxia Medical University prior to study conduct (No. 2017-013). Informed consent was obtained from all patients included in the study.