Smoking cessation is of paramount importance in the prevention of lung cancer. Attendance for cancer screening may provide a “teachable moment”. This study aimed to evaluate changes in smoking status following lung cancer screening in a large group of both current and ex-smokers. 1520 subjects were enrolled and underwent low dose spiral chest CT scan screening for lung cancer. 97% returned at 1 year follow up for assessment of smoking status (confirmed in 48% by exhaled CO measurement) and were included in the analysis. Baseline characteristics predictive of abstinence from smoking were identified using logistic regression. Variables studied included age, sex, average number of cigarettes per day, number of years smoked, FEV₁ (% predicted), results of the baseline screening test and, for ex-smokers, duration of abstinence at baseline.

14% of the 901 baseline current smokers were abstinent at follow up, higher than the expected rate of 5–7% in a general population. After adjusting for other potential variables, lower FEV₁ % predicted was the only significant predictor of abstinence from smoking at 1 year. 10% of the 574 baseline ex-smokers had resumed smoking, similar to rates seen in smoking cessation programmes. A longer duration of abstinence at baseline was the only significant predictor of continued smoking abstinence.

Since the abstinence rate was higher than in a general population and a negative screening test did not affect the quit rate, the authors conclude that screening is an opportunity to provide additional assistance in smoking cessation and to implement relapse prevention measures in former smokers. However, since the study did not include a comparison group of subjects without CT scan screening, a direct evaluation of the role of this intervention in changing smoking status is not possible.