Geographical Discrepancy in Medical Care Access Among Children, Adolescents, and Young Adults With Cancer in Japan, 2016–2019

In Japan, cancer control measures have been developed in specialized hospitals for children (0-14 years), and adolescents and young adults (15-39 years) patients with cancer. We investigated geographical discrepancies between residential addresses and cancer treatment hospitals in patients aged 0-39 in Japan between 2016 and 2019. Using Japan's National Population-Based Cancer Registry data (n = 99,968), we classified the cases into 10 diagnostic groups and four age groups: 0-14, 15-19, 20-29, and 30-39. Using five types of hospital groups, we examined the origin-destination relationships between patients' residences and hospitals at the prefecture and Secondary Medical Area (SMA) levels via cross-tabulation, summarizing the results using descriptive statistics and heat maps. Generalized Estimating Equation analysis was performed to investigate the factors associated with receiving treatment outside the residential prefecture based on individual data. The median percentage of patients receiving treatment within their residential prefecture was 81.82% or higher across age groups and hospital groups. At the SMA level, the percentage ranged from 0% to 57.00% (median)-minimum 0.0% and maximum 100.0%. Model analysis revealed that patients with retinoblastoma (adjusted risk ratio: 5.45) and those living in metropolitan (Tokyo: 3.73, Osaka: 2.00) and non-metropolitan and depopulated (1.67) areas were significantly more likely to travel outside their residential prefectures. These findings reveal that Japan faces geographical discrepancies in access to cancer care, particularly for specific cancer types and areas. These findings can inform targeted interventions to support equitable access to specialized cancer care for young Japanese patients.