Our understanding of the etiology of EGFR mutant lung cancer remains incomplete. One persistent finding in the literature is the geographic variation in the frequency of EGFR mutations in lung adenocarcinoma. We investigated the association between two biomarkers of East Asian ancestry, the genetic polymorphisms EDAR V370A and ABCC11 G180A, and the frequency of EGFR mutations in lung adenocarcinoma patients in a range of countries. The Pearson's linear correlation between the frequency of EGFR mutations and the EDAR polymorphism was 0.92 (P < 2.2 x 10-10) and for the ABCC11 polymorphism it was 0.72 (P < 1.6 x 10-4). These results suggest that the variation in the measured frequency of EGFR mutations in lung adenocarcinoma can be explained, at least in part, by interethnic genetic variation. To improve our understanding of this disease, studies exploring the genetic polymorphism(s) that cause these interethnic differences, as well as the mechanisms of actions through which they work, are warranted.