Geographic Access to Cancer Care and Treatment and Outcomes of Early-Stage Non-Small Cell Lung Cancer.

Importance: Data on the impact of geographic access to cancer care on early-stage non-small cell lung cancer (NSCLC) treatment and outcomes are limited. Objective: To examine the associations of geographic access to cancer care with guideline-recommended treatment and outcomes in patients with early-stage NSCLC. Design, Setting, and Participants: This population-based cohort study included patients with early-stage NSCLC newly diagnosed between January 1, 2007, and December 31, 2015, followed up through December 31, 2016, and identified from the Surveillance, Epidemiology, and End Results dataset. Data analysis was performed from March to November 2024. Exposures: Geographic access to thoracic surgeons and radiation oncologists was quantified using the 2-step floating catchment area algorithm and categorized into quintile 1 (least access) through quintile 5 (greatest access). Main Outcomes and Measures: Multilevel logistic regression was performed to estimate odds ratios (ORs) of receipt of surgery and radiotherapy. Hazard ratios (HRs) of lung cancer-specific mortality were estimated using Fine and Gray subdistribution hazard regression. Results: Among 65 259 patients, the mean (SD) age was 69.4 (10.1) years; 33 114 patients (50.7%) were female, 1071 (1.6%) were uninsured, and 7541 (11.6%) were enrolled in Medicaid. The least (vs greatest) geographic access to thoracic surgeons (HR, 1.10; 95% CI, 1.03-1.18; P < .001 for trend) and radiation oncologists (HR, 1.11; 95% CI, 1.04-1.18; P < .001 for trend) was associated with higher lung cancer mortality. Patients in counties with the least (vs greatest) access to thoracic surgeons were less likely to undergo surgery (OR, 0.80; 95% CI, 0.69-0.93; P < .001 for trend); this association was much stronger in Asian than non-Hispanic White patients and in Medicaid-insured than non-Medicaid-insured patients. Although there was no significant association overall, geographic access to radiation oncologists was significantly associated with radiotherapy use in older (OR, 0.85; 95% CI, 0.76-0.95), Hispanic (OR, 0.65; 95% CI, 0.49-0.86), and uninsured (OR, 0.63; 95% CI, 0.43-0.94) patients. Conclusions and Relevance: In this cohort study, geographic access to cancer care was associated with guideline-recommended treatment for early-stage NSCLC and outcomes, particularly in socially marginalized patients, underscoring the importance of ensuring appropriate geographic allocations of cancer care resources and addressing travel barriers to health care to improve NSCLC treatment, prognosis, and equity.