Organized Lung Cancer Screening Pilot: Informing a Province-Wide Program in Ontario, Canada

Background: Lung cancer is the leading cause of cancer deaths in Ontario. The National Lung Screening Trial demonstrated that screening with low-dose computed tomography (LDCT) reduces lung cancer mortality.

Methods: In June 2017, Ontario Health (Cancer Care Ontario) initiated a pilot for lung cancer screening to inform implementation of a province-wide initiative. The screening pathway includes targeted recruitment strategies, the Tammemägi risk prediction model (PLCOm2012) to determine eligibility, opt-out smoking cessation services for all current smokers, use of the Lung-RADS scoring system to guide abnormal results management, and screening navigators providing end-to-end support. Referral criteria include being 55 years of age to 74 years of age and a current or former daily cigarette smoker for greater than or equal to 20 years, while the screening eligibility criterion is a PLCOm2012 risk greater than or equal to 2% in 6 years. Selected results of the interim pilot evaluation are presented. Four hospitals contributed data in the first year of the pilot.

Results: During 2017 to 2018, 4205 Ontarians were recruited, 3234 risk assessments were conducted, and 2151 (66.5%) individuals were eligible for screening. Baseline LDCT scans were performed in 1624 (50.2%) individuals. Diagnostic evaluation in 120 (7.4%) individuals identified 28 (1.7%) with lung cancer, and proportions of stage I to II and stage III to IV were 71% and 29%, respectively. Of those recruited, 1443 (34.3%) individuals were smokers and 1326 (91.9%) accepted smoking cessation services.

Conclusions: The pilot is the largest in Canada and aligns with International Agency for Research on Cancer standards for population-based, organized cancer screening. Recruitment of high-risk individuals, high rates of smoking cessation program acceptance, and detection of early-stage cancers are demonstrated.