Abstract 3619: Urban-rural variations in racial/ethnic differences in time to treat among individuals newly diagnosed with cancer in the United States 2015-2021

Abstract Timely treatment is crucial for effective cancer care. Studies have shown longer durations from diagnosis to treat among non-white racial/ethnic groups in the United States. In this study, we assessed whether racial/ethnic differences in the time to treat vary across urban/rural residents. We conducted a retrospective cohort study of over 3.5 million individuals newly diagnosed with cancer from 2015 to 2021, using data from the Surveillance, Epidemiology, and End Results (SEER) program. We estimated the median number of days from diagnosis to treatment by five racial/ethnic groups (non-Hispanic [NH] white, NH black, NH American Indian/Alaskan Native, NH Asian and Pacific Islander, and Hispanics) and five strata of urban/rural classifications of residence (large, mid-sized, small, adjacent, and non- metropolitan areas). NH black individuals living in large metropolitan areas experienced the longest median duration from diagnosis to treatment initiation (33 days), which was 8 days (95% CI=7.8, 8.2) longer than NH white individuals in large metropolitan cities. Longer durations among NH black were also present among those who live in mid-sized (6 days difference, 95% CI=5.6, 6.4), small (6 days, 95% CI=5.4, 6.6), adjacent (4 days, 95% CI=3.4, 4.6), and non-metropolitan areas (5 days, 95% CI=3.9, 6, .1), albeit smaller in size. Among Hispanic individuals newly diagnosed with cancer, those in large to small metropolitan cities also experienced longer duration from diagnosis to treatment when compared to NH white individuals in those areas (coef.=3 days [95% CI=2.8. 3.2], 2 days [95% CI=1.7, 2.3], and 3 days [95% CI=2.4, 3.6] for large, mid-sized, and small metropolitans); those in adjacent and non-metropolitan areas had slightly shorter duration from diagnosis to treatment (coef.=-1 day [95%=-1.7, -0.3] and -1 day [95% CI=-1.9, -0.1] respectively). NH American Indian/Alaskan Native also experienced longer duration from diagnosis to treatment compared to NH white individuals, and there were no variations across urban/rural areas. Similarly, NH Asian and Pacific Islander individuals had an estimated 3 days longer duration from diagnosis to treatment regardless of their residential areas, except that those who lived in non-metropolitan areas experienced even longer delays (coef.= 7 days [95% CI=5.7, 8.3]) compared to NH white individuals. This study highlights significant racial/ethnic disparities in time to cancer treatment, particularly for NH black individuals in large metropolitan areas. Addressing these disparities is essential for improving cancer care equity. Citation Format: Hui Cheng, Oxana Palesh, Susan Hong. Urban-rural variations in racial/ethnic differences in time to treat among individuals newly diagnosed with cancer in the United States 2015-2021 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3619.