Trends in initial primary treatment approach and biomarker testing across social determinants of health in early-stage non-small cell lung cancer

To evaluate the impact of a comprehensive set of social determinants of health (SDOH) on treatments, timing, and key biomarker testing for early-stage non-small cell lung cancer (NSCLC). Patients with the first diagnosis of stage I–III NSCLC from 1 January 2015 to 15 October 2023 and treated at community health systems in the United States were eligible for this retrospective database study. We summarized initial primary treatment and time-to-treatment initiation (TTI) by Social Vulnerability Index (SVI), primary care provider (PCP) shortage areas, household income, and insurance type. Data cutoff was 15 October 2024. Of 8501 patients with stage I–III NSCLC, 32% underwent surgery-only and 14% also received neoadjuvant and/or adjuvant therapy. Greater percentages underwent surgery (with/without neoadjuvant/adjuvant therapy) in counties with lowest SVI/vulnerability, highest median income, and no PCP shortage, and among those with private healthcare insurance (vs. Medicare/Medicaid). Median (range) TTI for any NSCLC-related treatment after diagnosis was 41 days (0–1846); TTI increased across treatment strategies by increasing SVI/vulnerability and decreasing household income. Annual rates of programmed death-ligand 1/<i>EGFR</i> mutation testing rose from 60%/51% in 2020 to 84%/82% in 2023, with greatest rates in counties with no PCP shortage. Disparities in early-stage NSCLC treatment by SDOH factors call for efforts to improve access to timely care for NSCLC. The survival rate for non-small cell lung cancer (NSCLC), the most common lung cancer type, has been improving in the United States over the past decade. This is because better treatments are available and also because of earlier diagnoses, when the disease is easier to treat. However, prior studies have reported that patients who have poor so-called ‘social determinants of health’ (SDOH)—such as food insecurity, living in socioeconomically disadvantaged areas, or belonging to certain racial or ethnic minority groups—are more likely to have later NSCLC diagnosis, delays in starting treatment, and worse survival. The goal of our study was to update these earlier findings with more recent patient data (2015–2024) to evaluate SDOH factors for their impact on treatments, timing, and key tests for early-stage NSCLC. We found that patients with early-stage NSCLC who lived in counties or areas with lowest social vulnerability, highest median income, and no primary care provider shortage, and those who had private healthcare insurance (instead of Medicare or Medicaid) more commonly had surgery and started treatment sooner for their NSCLC. Instead, the opposite was true for patients who lived in areas with highest vulnerability, lowest income, and shortages of primary care doctors, and who had Medicare or Medicaid insurance: they more commonly had no initial primary treatment. Moreover, the average time until starting treatment increased with greater social vulnerability and less household income. These findings call for improving patient access to timely care for NSCLC.