Geographic Access, Transportation Resources, and Early-Stage Lung Cancer Treatment Among Socioeconomically...

A recent study reported that geographic access to cancer care was associated with guideline-recommended treatment for early-stage non-small cell lung cancer (NSCLC), particularly among uninsured and Medicaid patients.

To examine whether transportation resources modify the association between geographic access and treatment for early-stage NSCLC.

We used Surveillance, Epidemiology, and End Results data linked with Medicaid Analytic eXtracts Personal Summary files to identify patients aged 18 years or above with stage I/II NSCLC diagnosed during 2007-2019 who were uninsured or had Medicaid as primary/secondary payers at diagnosis. Geographic access to thoracic surgeons (TS) and radiation oncologists (RO) was calculated using the 2-step floating catchment area method and categorized into quartiles. Transportation resources were evaluated as county-level vehicle ownership and public transit availability, both dichotomized at the median level. Poisson regression with county-level clustering estimated rate ratios (RRs) for surgery and radiotherapy.

Geographic access to TS was associated with surgery in both low (RR=0.92, 95% CI: 0.87-0.97 for lowest vs. highest access; P=0.66 for interaction) and high (RR=0.91, 95% CI 0.87-0.96) vehicle ownership counties. In contrast, geographic access to RO was associated with radiotherapy only among patients in counties with low vehicle ownership (RR=0.81, 95% CI: 0.74-0.89; P=0.01 for interaction), but not those in counties with high vehicle ownership (RR=0.96, 95% CI: 0.88-1.04). Similar patterns were observed in metropolitan counties with low vehicle ownership and limited public transit availability.

Local transportation resources modified the association between geographic access and radiotherapy, but not surgery. Improving transportation access may enhance radiotherapy use for NSCLC.