Lung cancer screening's effect on smoking cessation: A longitudinal analysis of randomized screening trial

Background: In order to examine whether lung cancer screening encouraged smoking cessation, this study analyzes smoking patterns among the participants in the cancer screening program of Mayo Lung Project. Method: Mayo Lung Project randomized 11122 male smokers and ex-smokers into a control group whereby subjects received a baseline screening (chest X-ray) and an intervention group whereby subjects received the baseline screening plus six years of routine screening. Annual surveys during the six-year intervention asked the subjects about the average number of cigarettes smoked per day during the last year. Longitudinal mixed models were used to examine the trends of smoking cessation and smoking intensity (measured by the daily consumption of cigarettes) among the subjects. Results: After the baseline screening, there was a significant decline in average number of smoking in both arms of this lung cancer screening trial (p<.001). However, for the following six years we found no significant difference in abstinence behavior between the intervention group and the control group (p=.59). While we detect that the continuing smokers in the intervention group smoked significantly more than their counterparts in the control group (p<.01), the magnitude of the difference (one cigarette per day) was not clinically important in explaining differences in lung cancer incidence and mortality. Conclusion: A baseline lung cancer screening to smokers could lead to smoking cessation among smokers, but multi-year routine lung screening programs might necessarily add to the cessation effect. This study recommends that smoking cessation interventions be integrated in routine lung cancer screening programs.