Background

Lung cancer (LC) represents a major clinical and economic burden in Ireland. In view of the upcoming introduction of the national lung cancer screening programme, missing per-patient cost estimates form a key evidence gap for cost-effectiveness analyses of the screening evaluation. 

Objectives

To estimate stage-specific healthcare costs of lung cancer in Ireland over five years following diagnosis, focusing on costs incurred among patients alive, and to characterise uncertainty around these estimates for use in future economic evaluations.

Methods

We developed a patient-level microsimulation model of newly diagnosed lung cancer patients, stratified by stage at diagnosis (I–IV). Individual treatment pathways were simulated across multiple lines of care, including surgery, chemotherapy, radiotherapy, immunotherapy, targeted therapy, best supportive care, and system-level services (diagnostics, recurrence management, ongoing follow-up, and treatment administration). Progression-free survival was modelled using parametric survival functions calibrated to registry-based data and validated against National Cancer Registry Ireland survival estimates.

Costs were assigned from the public payer perspective at the patient × month × service level. Monthly costs were aggregated as mean costs per patient alive in each month, ensuring estimates reflect the intensity of care among survivors rather than dilution by mortality. Results were summarised as stage-specific annual costs (years 1–5) and as mean monthly costs in the first six months following diagnosis versus subsequent months. Parameter uncertainty was explored using one-way sensitivity analysis and probabilistic sensitivity analysis.

Results

Five-year healthcare costs per patient alive increased substantially with stage at diagnosis, from approximately €30,800 in Stage I to €230,900 in Stage IV. Across all stages, costs were highest in the first year after diagnosis, accounting for the largest share of total expenditure (Stage IV year-1 cost: approximately €60,500). Mean monthly costs in the first six months ranged from €2,400 in Stage I to €4,400 in Stage IV, reflecting intensive initial treatment. In advanced disease, costs remained high beyond six months (Stage IV: approximately €3,800 per month), driven by prolonged systemic therapy. Probabilistic sensitivity analysis showed relatively narrow uncertainty around mean estimates, while one-way sensitivity analysis identified immunotherapy prices, administration costs, and late-line treatment probabilities as key cost drivers.

Conclusions/Implications

Among patients alive, lung cancer costs in Ireland are strongly stage-dependent, with advanced disease associated with prolonged and substantial expenditure. The results have important implications for health policy, highlighting the economic consequences of late diagnosis and providing essential inputs for future cost-effectiveness analyses of the screening programme.