Abstract 1464P
Background
Asian ethnicity has been reported to play a role in presentation and to be an independent predictor of survival for gastric cancer, leading some to suggest that Asian and non-Asian populations should be treated differently. The purpose of this study was to study differences in presentation, treatment and outcomes of these patients at a single Canadian cancer center, located in a city with a large Asian community.
Methods
A retrospective database analysis of patients with de novo metastatic GEJ and gastric adenocarcinoma, treated between 2008 and 2016, was performed. Ethnicity, defined as Asian and non-Asian, was identified by patient report. Kaplan-Meier (KM) and (univariable and multivariable) Cox proportional hazards models were fitted to assess association between ethnicity and other clinical factors with overall survival (OS) and progression free survival (PFS).
Results
Of 495 patients included in the study, 14% were Asian and 86% non-Asian. The Asian patients were more likely to be overweight (p<0.001) and to receive systemic chemotherapy (p=0.0088). They were less commonly diagnosed with tumors of the GEJ (p<0.001). Patients were treated the same way irrespective of ethnicity, most frequently with a platinum-based triplet. The median OS was 10.6 months for Asians and 9.6 months for non-Asians (p=0.9) and median PFS was 6 months and 6.3 months (p=0.0582), respectively. Asian ethnicity was not an independent predictive factor for mortality (hazard ratio (HR) 1.21; 95% confidence interval (CI), 0.63 to 2.33; p=0.56) nor for PFS (HR 1.18; 95% CI 0.65 to 2.15; p=0.58). An interaction between Asian ethnicity and chemotherapy efficacy was not observed. On multivariate analysis only ECOG and number of metastatic sites of disease were shown to be independent prognostic factors for OS.
Conclusions
Our study suggests that there are differences in clinical and tumor characteristics at presentation between Asian and non-Asian populations, but this does not translate into differences in outcome. Asian ethnicity was not demonstrated to be an independent prognostic factor for PFS nor OS. Asian ethnicity should not be a factor to consider when deciding on best treatment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
E. Elimova: Advisory/Consultancy, Research grant/Funding (self): BMS; Advisory/Consultancy, Research grant/Funding (self): Zymeworks. All other authors have declared no conflicts of interest.