Ethnic differences in survival outcome in patients with advanced stage non-small cell lung cancer: Results of a meta-analysis of randomized controlled trials

Introduction: Although interethnic differences in survival to cytotoxic chemotherapy in patients with non-small cell lung cancer exist, an analysis of survival outcomes based on ethnicity has not yet been fully evaluated systematically using large patient cohorts. Furthermore, recent trial results may be confounded by the use of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). Methods: A meta-analysis was performed using trials identified through MEDLINE. Summary data on median overall survival (OS), time to progression, progression-free survival, and overall response rate (ORR) were collected from randomized controlled trials. Outcomes were compared between Asian and Caucasian studies. Results: Of the 1182 citations identified, 391 treatment arms (Asian 90 and Caucasian 301) were analyzed. The median OS and ORR in Asian and Caucasian studies for all chemotherapy regimens was 10.1 and 8.0 months (p < 0.001) and 32.2 and 25.9% (p < 0.001), respectively. The median OS in Asian and Caucasian studies for monotherapy, platinum doublets, and three drugs or more combination was 9.9 and 6.8 months, 10.4 and 8.6 months, and 9.4 and 8.0 months, respectively (all p < 0.001). In studies published pre-EGFR TKI, the median OS and ORR in Asian and Caucasian studies for all chemotherapy regimens was 9.1 versus 7.3 months (p < 0.001), respectively, and 29.0 and 23.0% (p < 0.006), respectively. The median OS in Asian and Caucasian studies for monotherapy, platinum doublets, and three drugs or more combination pre-EGFR TKI was 8.9 and 6.5 months (p < 0.005), 9.1 and 7.5 months (p < 0.001), and 9.3 and 7.6 months (p < 0.003), respectively. In third-generation platinum doublets, the median OS in Asian and Caucasian studies was 11.3 and 9.5 months (p < 0.001), respectively, and ORR was 35.0 and 29.8% (p < 0.001), respectively. Conclusion: Ethnic differences in survival and response rate to chemotherapy exist and should be considered in clinical trial designs especially in the global context.