Race/ethnicity and lung cancer survival in the United States: a meta-analysis

Purpose: Lung cancer mortality has been shown to vary by race and ethnicity in cancer registries; however, studies often do not account for smoking status. We sought to summarize the independent contribution of race and ethnicity to survival in US lung cancer patients, accounting for important variables including smoking status. Methods: PubMed was used to identify 1,877 potentially eligible studies of which 27 were included. Studies were excluded if they did not account for age, race and/or ethnicity, and smoking status. Fixed- and random-effects meta-analyses were conducted using the reported adjusted hazard ratios (HR) of Hispanic ethnicity and Asian and African-American race compared to Non-Hispanic whites (NHWs) on overall survival in lung cancer. Results: Hispanic ethnicity and Asian race were associated with decreased adjusted risk of death (Hispanic: N_studies = 5, N_subjects = 108,810, HR = 0.95, 95% CI 0.90–1.00; Asian: N_studies = 6, N_subjects = 128,950, HR = 0.86, 95% CI 0.81–0.90). The results were similar when excluding studies of solely never-smokers. There was no significant difference in survival between African-American and white race after adjustment (N_studies = 10, N_subjects = 131,378, HR = 0.98, 95% CI 0.96–1.01). Other prognostic factors were female gender (HR = 0.88, 95% CI 0.87–0.89), unmarried status (HR = 1.08, 95% CI 1.04–1.11), ever-smoking status (HR = 1.11, 95% CI 1.08–1.15), having comorbidities (HR = 1.39, 95% CI 1.24–1.56), and treatment receipt (surgery: HR = 0.33, 95% CI 0.32–0.34; radiation: HR = 0.87, 95% CI 0.85–0.88; chemotherapy: HR = 0.64, 95% CI 0.63–0.65). Conclusions: Even after adjustment for clinical factors and smoking status, Hispanics and Asians experienced improved survival compared to NHWs. Future studies are needed to elucidate the drivers of these survival disparities.