Geographic Disparities in Access to Oncologists and Association with Cancer Outcomes in the United States.

BACKGROUND: Access to oncologists is crucial to quality cancer care. We aimed to assess the geospatial distribution of oncologists in the United States and its association with cancer mortality. METHODS: We used county-level oncologist data from the 2025 Doctors and Clinicians national downloadable file and county-level cancer outcome data from the 2018-2022 State Cancer Profiles. We assessed urban-rural differences in the distribution of oncologists in the United States and used Local Moran's I to identify clusters of high and low oncologist density and cancer mortality rates. We classified counties using the 2023 Rural-Urban Continuum Codes (RUCC) with RUCC 1-3 as urban and RUCC 4-9 as rural. RESULTS: 13,332 oncologists were identified nationwide. The median oncologist density per 100,000 population was 6.0 in urban counties and 0.0 in rural counties (p-value <0.001). The median age-adjusted cancer mortality rate per 100,000 population was 156.1 in urban counties and 166.8 in rural counties (p-value <0.001). Clusters of low oncologist density were observed in the South. CONCLUSION: There are significant geospatial differences in oncologist accessibility and cancer outcomes. Targeted interventions are necessary to ensure that rural areas maintain access to oncology care.