Quitting smoking improves two-year survival after a diagnosis of non-small cell lung cancer.

BACKGROUND: Smoking at diagnosis is associated with worse survival in lung cancer but the effects of quitting smoking on survival remain unclear. METHODS: In a UK multi-centre study (NCT01192256) we followed all 2751 patients with newly diagnosed non-small cell lung cancer (NSCLC) for up to 2 years or until death as part of the observational trial. Patients were offered smoking cessation advice and treatments according to national guidelines and local services. Smoking status was verified by exhaled carbon monoxide levels. Kaplan-Meier survival analysis and Cox Proportional Hazards Modelling examined the effects of quitting smoking on survival at 2 years. FINDINGS: 646 were current smokers at the time of diagnosis. The unadjusted two-year Kaplan-Meier survivor functions for quitters (0.45, 95 %CI 0.37 to 0.53) and continuers (0.32, 0.28 to 0.36) were significantly different (log-rank test p < 0.01). Median survival times were 659 days for quitters and 348 days for continuers. After adjusting for age, sex, stage, performance status, curative intent surgery, radical radiotherapy and comorbidity, the hazard ratio for quitting at diagnosis (0.75, 95 % CI 0.58 to 0.98) indicated a statistically significant reduction in the risk of death across the two-year study period. INTERPRETATION: Quitting smoking is independently and significantly associated with improved survival regardless of stage in NSCLC. We recommend that smoking cessation advice and treatments should be offered to smokers with lung cancer. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT01192256. FUNDING: This work was supported by a 2010 Global Research Award for Nicotine Dependence (GRAND), Pfizer.

Longitudinal study to assess impact of smoking at diagnosis and quitting on 1-year survival for people with non-small cell lung cancer.

OBJECTIVES: To update the prevalence of smoking in people as they were diagnosed with non-small cell lung cancer (NSCLC) and to see whether smoking status at baseline and quitting are independently associated with 1-year survival. DESIGN: A real-world cohort study following patients from diagnosis for up to 1 year or until death. SETTING: UK multi-centre study (28 sites) based in secondary and primary care. PARTICIPANTS: 1124 patients with newly diagnosed NSCLC between 2010-2016. MAIN OUTCOME MEASURES: Smoking status was validated at diagnosis and at every routine and emergency hospital visit. Cancer treatments were offered according to local multi-disciplinary team decisions following UK guidelines and smoking cessation treatments offered according to local practice /availability. Survival analysis and Cox Proportional Hazards Modelling examined the associations of a) smoking at baseline and b) quitting smoking, on survival at 1 year. RESULTS: 77% of never smokers, 60% of ex-smokers and 57% of current smokers, were alive at 1 year (p = 0.01). After adjusting for age, stage, EGOG, surgery and gender, ex smokers (adjusted HR 1.96, 95% CI 1.16-2.31) and current smokers (aHR 2.04, 1.19-3.48) were both more likely to die within one year. 23% of smokers with NSCLC quit within 3 months of diagnosis. At 1 year, 69% of those who quit were alive versus 53% of those who continued to smoke (p < 0.01). After adjusting the risk of dying was lower (aHR 0.75), in those who quit smoking, although this was not statistically significant (p = 0.23). CONCLUSIONS: This is the largest prospective study that validates smoking in NSCLC; it shows a third of people are smoking at the time of diagnosis. Smokers have lower 12-month survival than never and ex -smokers. Quitting smoking was associated with 25% reduction in mortality which may be clinically important although not statistically significant, after adjusting for other factors.