The effect of cigar, cigarillo and pipe smoking on lung cancer risk and screening eligibility.
BACKGROUND Smokers are eligible for lung cancer screening using low dose CT (LDCT) if they have a sufficiently high risk of lung cancer. In England, for example, people are eligible if their estimated risk using either of two validated models (PLCOm2012 and Liverpool Lung Project) exceeds a certain threshold. Risk is often estimated using only cigarette consumption (duration and number per day), yet many smokers also use other cancer-causing tobacco products. METHODS SUMMIT is a prospective cohort study of a LDCT screening service. We evaluated the impact of cigars, pipes, and cigarillos on lung cancer risk. RESULTS Among 13,000 participants who were current/former cigarette smokers, 511 (1 in 25) were also regular users of cigars, pipes, or cigarillos. The 5-year cumulative lung cancer incidence in people who currently smoked both types of tobacco products was 8.85%, versus 5.74% for cigarette only current smokers. Among these 511 participants, the percentage whose risk was below the screening eligibility threshold ignoring other tobacco products which then exceeded the threshold including these products was 0.6% using LLPv2, and 8.2% using PLCOm2012. CONCLUSIONS All tobacco consumption should be considered when determining screening eligibility to avoid missing those who can benefit from LDCT. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov no: NCT03934866.