Quitting Smoking and Two-Year Survival After a Diagnosis of Small-Cell Lung Cancer

Smoking at diagnosis is associated with worse survival in non-small-cell lung cancer, and quitting is independently associated with better 2-year survival. The effects of smoking status at baseline and smoking cessation on small-cell lung cancer (SCLC) outcomes are unclear.

In a subgroup of a large UK multicenter lung cancer study, we report outcomes at 2 years for 720 patients newly diagnosed with SCLC. All were offered smoking cessation advice and cancer treatments according to national guidelines. Smoking status was verified by exhaled carbon monoxide at all visits. Kaplan-Meier survival analysis and Cox Proportional Hazards Modeling examined the effects of smoking status at baseline and the effects of quitting smoking on survival at 2 years.

There was no difference in survival rates between never (0.32, 95% CI 0.14-0.51), ex (0.24, 0.20-0.28), current (0.26, 0.21-0.31) smokers with SCLC at 2 years (P = .29). Those with limited SCLC (n = 84) lived significantly longer before smoking status was verified at 3 and 6 months. In this group, after adjusting for age, sex, stage, performance status, and comorbidity, the hazard ratio for quitting at diagnosis (0.36, 95% CI, 0.11-1.11) indicated a trend but no statistically significant reduction in the risk of death at 2 years (P = .08). Median survival times were 503 days for quitters and 431 days for continuers.

Quitting smoking appears to have a positive effect on survival in limited disease SCLC, but larger numbers and longer follow-up are needed.

ClinicalTrials.gov, identifier NCT01192256.