Relationship between West African ancestry with lung cancer risk and survival in African Americans

Purpose: African Americans, especially men, have a higher incidence of lung cancer compared with all other racial and ethnic groups in the US. Self-reported race is frequently used in genomic research studies to capture an individual’s race or ethnicity. However, it is clear from studies of genetic admixture that human genetic variation does not segregate into the same biologically discrete categories as socially defined categories of race. Previous studies have suggested that the degree of West African ancestry among African Americans can contribute to cancer risk in this population, though few studies have addressed this question in lung cancer. Methods: Using a genetic ancestry panel of 100 SNPs, we estimated West African, European, and Native American ancestry in 1,407 self-described African Americans and 2,413 European Americans. Results: We found that increasing West African ancestry was associated with increased risk of lung cancer among African American men (OR_{Q5 vs Q1} = 2.55 (1.45–4.48), p = 0.001), while no association was observed in African American women (OR_{Q5 vs Q1} = 0.90 (0.51–1.59), p = 0.56). This relationship diminished following adjustment for income and education. Conclusions: Genetic ancestry is not a major contributor to lung cancer risk or survival disparities.