Mapping Low-Dose Computed Tomography Lung Cancer Screening in Canada: A Scoping Review of Implementation, Eligibility, Access, Outcomes, Barriers, Facilitators, and Equity

Abstract

Background. Lung cancer is the leading cause of cancer-related death in Canada, with a five-year survival of approximately 14% driven by late-stage diagnosis (Canadian Agency for Drugs and Technologies in Health, 2015). Low-dose computed tomography (LDCT) screening reduces lung cancer mortality by 20-24% in high-risk populations (Usman Ali et al., 2016). As Canadian provinces transition from research pilots to province-wide programs, evidence on LDCT implementation, eligibility, equity, and outcomes is dispersed across pilot reports, microsimulations, and qualitative work.  Objective. To map and synthesize Canadian and Canadian-relevant evidence on LDCT lung cancer screening across seven domains: program implementation, eligibility, access, outcomes, barriers, facilitators, and equity.  Methods. A PubMed search retrieved 66 records; dual-reviewer title-and-abstract screening retained 49, and all confirmed at full-text review by four reviewers. Inclusion required adults ≥18, Canadian setting or transferability, LDCT screening intervention, and publication 2010 onward. Data on jurisdiction, design, population, and findings were extracted and thematically organized against the seven domains.  Findings. Outcomes (n = 28) and implementation (n = 20) had the most evidence; equity (n = 4), access (n = 4), and barriers (n = 3) were the least studied. Risk-based eligibility tools, particularly PLCOm2012, consistently outperformed smoking-history thresholds and were validated in Quebec (Jantzen et al., 2023), Alberta (Tremblay et al., 2023), and Ontario (Tammemägi et al., 2024) cohorts. The Ontario Lung Cancer Screening Pilot enrolled 7,768 high-risk individuals using PLCOm2012noRace, screened 4,451 Canadians with a high-quality follow-up, and demonstrated the feasibility of opt-out smoking-cessation referral and screening navigators (Darling et al., 2021; Tammemägi et al., 2024; Walker et al., 2023). Microsimulation analyses using the Cancer Risk Management Model and OncoSim consistently projected LDCT to be cost-effective in Canadian publicly funded systems, with savings amplified when smoking cessation and adapted screening intervals were integrated (Evans et al., 2020; Goffin et al., 2015; Tabarsi et al., 2022). Synoptic radiology reporting was deployed in Alberta, McGill, and Ontario programs and reduced reporting omissions in approximately 70% of audited reports (Bedard et al., 2022). Identified barriers included primary-care knowledge gaps (Lofters et al., 2019), inadequate nodule follow-up adherence (Yi et al., 2019), and psychosocial impacts after positive results (Tammemägi et al., 2019). Equity-oriented qualitative work in Toronto demonstrated that poverty, food insecurity, transportation, and stigma deter participation among the highest-risk populations (Lofters et al., 2021).  Conclusions. Canadian evidence robustly supports province-wide LDCT screening implementation built on risk-based eligibility, integrated cessation, and synoptic reporting. Equity, access, and patient-experienced barriers remain underexamined and represent priority areas for future Canadian research and program design.  Keywords: lung cancer screening; low-dose computed tomography; Canada; PLCOm2012; health equity; smoking cessation; scoping review; cancer prevention