Smoking habits are an independent prognostic factor in patients with lung cancer

Objectives The role of tobacco in the pathogenesis of lung cancer (LC) has been clearly established. Based on the epidemiological evidence that smoking may influence LC progression, we investigated the idea that smoking behavior could be associated with overall survival (OS) in this group of patients. Methods A total of 351 patients with LC (311 men and 40 women) were reviewed. Smoking status was assessed as tobacco users or non‐users. To calculate pack‐years of smoking, the average of number of cigarettes smoked per day was divided by 20 to give packs per day, and then multiplied by the total number of years of smoking. OS was the main outcome measure. Results The mean follow‐up was 3.3 ± 1.2 years. Kaplan–Meier plots of OS by use of tobacco revealed significant differences by smoking status (log‐rank = 5.44, P 7 pack‐years groups (log‐rank = 4.27, P