In conclusion, NSCLC patients who underwent surgical resection with smoking history can benefit from smoking cessation; former smokers with NSCLCs can age older at diagnosis, presenting an earlier TNM stage and more EGFR but less KRAS mutations than current ones with NSCLCs; and light former ones can have better long‐term overall survival than heavy former ones as well as light current ones. Here, KRAS is linked to non-small cell lung carcinoma.