The state of cancer treatment trials in America: A comparison of counties with and without active trials by demography and social vulnerability.
Authors: Kirkwood Margaret Kelsey , Schenkel Caroline , Bruinooge Suanna Steeby , Riffon Mark F. , Peppercorn Jeffrey M. , Subbiah Ishwaria M. , Waterhouse David Michael , Levit Laura A. 
Published: October 2023

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Background: Access to clinical trials is a pillar of high-quality cancer care, expanding patient treatment options. A key to trial access is having trials in one’s community. Methods: Trial registration data and other governmental sources were used to characterize the population, land area, rurality, social vulnerability and cancer incidence of US counties with and without local cancer treatment trials. Data from beta.clinicaltrials.gov was downloaded on May 16, 2023. Phase 1-3 cancer treatment trials that had a status of not yet recruiting, recruiting, active not recruiting, enrolling by invitation (collectively referred to as “active”) and geographic coordinates for at least one US site were identified. ArcGIS Pro was utilized to assign a county to each trial site and R statistical software to aggregate trials by county. The county-level trial data was linked to 2017-2021 population and land area data from the US Census, 2015-2019 age-adjusted incidence rates for all cancers from NCI/CDC State Cancer Profiles, USDA 2013 Rural Urban Continuum Codes (RUCC), and CDC/ATSDR 2020 Social Vulnerability Index (SVI) data. The SVI combines Census data, including race/ethnicity and socioeconomic factors, for overall and thematic social vulnerability indices. RUCC values were dichotomized to metro vs. nonmetro; high cancer incidence and high overall SVI counties were defined by fourth quartile values from all US counties. Results: Of over 452000 studies on clinicaltrials.gov, 7988 cancer treatment trials at 1871 US sites met the inclusion criteria for analysis. The majority (70%, 2195/3143) of counties did not have a single cancer treatment trial despite these counties being home to 54M US residents (17% of US population) and 2.6M square miles (74% of US land area). Less than a third (30%, 948/3143) of counties had at least one active trial site with a median of 66 active trials per county (IQR: 19, 152). Over half (53%, 341/647) of high cancer incidence counties and 73% (574/786) of high vulnerability counties had no active cancer treatment trials. Characterizing the rural trials access gap, we found that of the 1977 US nonmetro counties (where 14% of Americans reside by RUCC classification), 1683 counties (85%) had no active trials. Only 294 of the nonmetro counties (15%) had at least one trial site. In contrast, most metro counties (56%, 654/1166) had a trial. Of 77 nonmetro counties with both high cancer incidence and high SVI vulnerability scores, 62 (81%) had no active trials. Conclusions: Most US counties lack a single active cancer treatment trial, especially nonmetro and high vulnerability areas. Identifying these areas and understanding local barriers are crucial to decentralize clinical trials and expand trial infrastructure and training. ASCO is actively working to curate this data to aid oncology stakeholders amid their strategic planning for future studies.