Figure 1. Process of patient (female never smoker with lung adenocarcinoma) selection in this study.

(A) Distribution of lung cancer according to histology subtype. (B) Distribution of lung adenocarcinoma according to gender. (C) Distribution of lung adenocarcinoma from female according to smoking status. Patients with no medical record of smoking status were excluded. The record of year 2012 was not shown due to lack of smoking information.