Longitudinal study to assess impact of smoking at diagnosis and quitting on 1-year survival for people with non-small cell lung cancer. (March 2019) - Gemine, Rachel E.
Highlights: Stopping smoking after a diagnosis of lung cancer can improve survival in patients with lung cancer. Smoking cessation support uptake and abstinence rates in patients with lung cancer remains low. Cessation should be advised in all smokers diagnosed with lung cancer. Abstract: 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.