Regional Differences in the Clinical Presentation of Registry-Recorded Renal Cell Carcinoma and Area-Level Healthcare Resource Indicators: A Multicenter Study in Miyazaki, Japan

Abstract

Highlights What are the main findings? Among 540 protocol-eligible MUCD cases, patients registered in the Northern area more often presented with predefined local symptoms and had larger tumors after adjustment for age and sex and accounting for clustering by facility. Clinical M1 disease was numerically more frequent in the Northern area, although the evidence for a regional difference was weaker after accounting for facility clustering and multiple comparisons. What are the implications of the main findings? Urologist and physician availability was lower in the Northern area, but these area-level indicators do not directly measure individual healthcare access. Future studies should incorporate residential location, registry coverage, imaging and health-check utilization, referral pathways, and diagnostic intervals. Abstract Background/Objectives: Healthcare resources are unevenly distributed across Miyazaki Prefecture, Japan. We examined regional differences in the clinical presentation of renal cell carcinoma (RCC) recorded in the Miyazaki Urological Cancer Database (MUCD), together with area-level healthcare resource indicators. Methods: We performed a retrospective descriptive observational analysis of prospectively collected data from the multicenter MUCD registry. After deduplication and rechecking eligibility, 540 patients with a documented diagnosis date within the study period (1 April 2019–31 March 2024) were included (Central/Southern, n = 333; Western, n = 116; Northern, n = 91). The three main clinical outcomes were adjusted for age and sex, with clustering by registering facility taken into account. Results: Presentation with predefined local symptoms occurred in 18.6%, 19.0%, and 34.1% of patients in the Central/Southern, Western, and Northern areas, respectively. Compared with Central/Southern, the adjusted odds ratio for predefined local symptoms in the Northern area was 2.30 (95% CI, 1.39–3.81). Median tumor size was 3.8, 4.4, and 5.0 cm, respectively; the adjusted mean difference for Northern versus Central/Southern was 1.24 cm (95% CI, 0.65–1.82). Clinical M1 disease was recorded in 10.2%, 12.1%, and 19.8%, respectively; the global test accounting for facility clustering yielded p = 0.076, and the Holm-adjusted p value for Northern versus Central/Southern was 0.082. Urologist density in 2024 was 8.7, 8.0, and 5.3 per 100,000 population, respectively. Conclusions: Regional differences were observed in the clinical presentation of MUCD-recorded RCC and in area-level healthcare resource availability. These findings are descriptive and hypothesis-generating and do not show that differences in resource availability caused the observed clinical patterns.