Factors Associated With Smoking Cessation Attempts in Lung Cancer Screening: A Secondary Analysis of the National Lung Screening Trial

Abstract

Background: Lung cancer remains the leading cause of cancer-related mortality in the United States. The National Lung Screening Trial (NLST) demonstrated a 20% reduction in lung cancer mortality resulting from lung cancer screening (LCS) with an additive reduction from smoking abstinence. However, successful smoking cessation within LCS is variable.

Research question: What patient and treatment factors are associated with attempts to quit smoking among those screened for lung cancer?

Study design and methods: In a secondary analysis of the American College of Radiology Imaging Network arm of the NLST, patient demographics, patient smoking behaviors, and tobacco treatment variables were stratified by patient smoking status. The Cox proportional hazards ratio was used to evaluate each variable's effect on attempting to quit smoking.

Results: Seven thousand three hundred sixty-nine patients were smoking actively at enrollment in the NLST. Of the patients who reported they were smoking, 73.4% did not receive any pharmacologic tobacco treatment. More patients who attempted to quit received pharmacologic tobacco treatment than those who continued to smoke: (nicotine replacement therapy [NRT], 18.0% vs 12.4% [P < .01]; bupropion, 7.9% vs 6.9% [P = .02]; both NRT and bupropion, 5.6% vs 3.9% [P < .01]). Stable users were more likely to be women (47.8% vs 43.8%; P < .01), to be African American (8.2% vs 6.3%; P = .007), to be unmarried (43.2% vs 36.9% [P < .01]), and to have less than a college education (47.7% vs 42.3%; P < .01). Patients with high dependence who received dual therapy with bupropion and NRT showed the highest likelihood of quit attempt (hazard ratio, 2.07; 95% CI, 1.75-2.44).

Interpretation: In this analysis, only one-quarter of patients who underwent LCS and who smoked were treated with pharmacologic therapy, which is associated with increased likelihood of attempting to quit. Certain characteristics are associated with difficulty with attempting to quit smoking. Those with high nicotine dependence benefitted most from dual pharmacologic therapy.

Keywords: lung cancer, screening, smoking cessation.