Geographical Barriers to Accessing Specialty Cancer Care Among Adolescents and Young Adults with Acute Lymphoblastic Leukemia

Background Prior studies demonstrated that a minority of adolescents and young adults (AYA, age 15-39 years) with acute lymphoblastic leukemia (ALL) receive care at specialty cancer centers (SCC), defined as National Cancer Institute Designated Cancer Centers (NCIDCC) and/or Children's Oncology Group (COG) sites. Receipt of front-line ALL treatment at an SCC appears particularly important, as a significant survival benefit has been observed for AYA ALL patients treated at these sites. In this population-based analysis, we describe the geographical distribution of U.S. AYA ALL patients relative to SCCs and identify patients at risk of severe geographical barriers to SCC-level care. Although an association between NCI Community Oncology Research Program (NCORP) sites and AYA ALL outcomes have not, to our knowledge, been assessed, we also evaluated NCORP sites, as the NCORP program may offer an opportunity for clinical trial participation.

Methods We used data obtained from the North American Association of Central Cancer Registries (NAACCR) to identify the county at diagnosis of AYA ALL patients diagnosed between 2004-2016 across 43 U.S. states; 7 states did not release data (light gray in Figures). Addresses of NCIDCC, COG and NCORP sites were obtained from publicly available websites. Driving distance and travel time from counties where participants lived to the closest NCI, COG and NCORP sites were calculated for each individual. For Hawaii and Alaska only, straight line distances were calculated because distances between patients and facilities are separated by water, separated by another country or the counties are so large that counties centroids had to be moved long distances to attach to the road network. Geographic access to an SCC or NCORP site was mapped by county. Based on a combination of driving distance and the number of patients diagnosed within a county during our study period, we grouped each county as having excellent, mild, moderate or severe access issues (see Figure for definitions).

Results Among 11,813 AYA ALL patients, 43% were 25-39 years old, 66% were male, 33% were Hispanic, and 37% had public insurance. More patients lived in the West (30%), followed by the Northeast (22%), Southwest (17%), Midwest (16%), and Southeast (15%). A total of 1,537 U.S. counties were found to have at least one newly diagnosed AYA ALL patient; the largest patient population was present in Los Angeles County, CA (n=749). The distribution of U.S. AYA ALL patients relative to NCIDCC (Fig 1A), COG (Fig 1B), and NCORP centers (not shown) demonstrates that moderate/severe issues in geographical access to NCIDCC affects 43% of AYA ALL patients, relative to COG (19%) and NCORP (28%). Strikingly, 31%, 21% and 13% of patients would need to drive ≥ 1.5 hours one way to access the nearest NCIDCC, NCORP or COG center, respectively. In contrast, 43% of AYA ALL patients experience excellent geographical access to an NCIDCC, while 61% and 58% have excellent access to a COG or NCORP site, respectively.

Conclusions Although AYA ALL patients have experienced superior survival following treatment at an SCC, substantial geographical barriers exist to accessing this care across the U.S., particularly at NCIDCC. Broader geographical access to COG sites suggests some younger AYAs may benefit from consideration of referral to these pediatric centers. While NCORP centers appear more geographically accessible than NCIDCC, work is needed in order to understand whether these sites consistently provide comprehensive ALL care and clinical trial options across the U.S.

Muffly:Kite: Consultancy, Research Funding; Medexus: Consultancy; CTI Biopharma: Consultancy; Astellas: Consultancy, Research Funding; Jasper: Research Funding; Adaptive: Honoraria, Research Funding; BMS: Research Funding; Adaptive: Honoraria; UpToDate: Consultancy, Honoraria; Novartis: Research Funding; Pfizer: Consultancy; Amgen: Consultancy. Keegan:GRAIL: Other: Cancer Survivorship Advisory Board Meeting.