Annual Meeting of the NCI Cohort Consortium (Abstract Submission): Submission #12

Lightning Talks Abstract
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Presenter's First Name: : Marta
Presenter's Last Name:: Manczuk
Title (eg: professor, assistant professor, chair, etc):: Associate Professor
Degree(s): Ph.D.
Contact Email:: marta.manczuk@nio.gov.pl
Organization:: Maria Sklodowska-Curie National Research Institute of Oncology in Warsaw, Poland
Project Title:: Smoking cessation and all-cause and cancer-specific mortality in Poland: A target trial emulation
Additional Authors:
1. First Name: Magdalena 
   Last Name: Cedzynska
   Degree(s): Ph.D.
   Organization: Maria Sklodowska-Curie National Research Institute of Oncology in Warsaw, Poland
2. First Name: Irena
   Last Name: Przepiorka
   Degree(s): M.A.
   Organization: Maria Sklodowska-Curie National Research Institute of Oncology in Warsaw, Poland
3. First Name: Martin
   Last Name: Lajous
   Degree(s): M.D. Ph.D.
   Organization: National Institute of Public Health in Mexico

Abstract::
Background 
In Poland, 25% of adults are daily smokers. Estimating the impact of smoking cessation on mortality in the absence of randomized trials is critical to achieve the tobacco endgame (smoking prevalence <5%). 

Methods
We emulated a target trial to estimate the effect of smoking cessation on all-cause and cancer mortality, comparing current and former smokers from the Polish Cohort Study (PONS; n=13,148 women and men) at baseline in 2010. We estimated the 12-year risk difference (RD) using pooled logistic regression models, weighting participants by the inverse probability of treatment to address confounding by age, marital status, sex, education, alcohol, smoking years, and physical activity and inactivity. We constructed cumulative incidence curves under smoking and smoking cessation and stratified analyses by sex. 95% confidence intervals (95%CIs) were calculated using bootstrapping.

Results
Among 2,482 current and 4,258 former smokers, 636 deaths and 260 cancer deaths occurred. The 12-year mortality risk for current smokers was 12.6% (95%CI 11.3, 14.1) and for former smokers 7.8% (95%CI 6.9, 8.7). The RD was -4.9 percentage points (95%CI -6.7, -3.3). For men, the corresponding RD was -8.2 percentage points (95%CI -12.6, -4.8) and for women -3.5 (95%CI -5.6, -1.6). The 12-year cancer mortality risk for current smokers was 5.7% (95%CI 4.7, 6.8) and for former smokers 3.1% (95%CI 2.4, 3.6). The RD was -2.6 percentage points (95%CI -4.0, -1.4).  

Conclusion
Our estimates suggest that smoking cessation in Poland significantly reduces the absolute risk of mortality, and that quitting tobacco smoking may be particularly impactful in men.