Racial and rural-urban disparities in radiotherapy utilization for oral cavity and pharyngeal cancers: A SEER analysis from 2013-2022.

Abstract

e18101 Background: Head and neck cancers accounted for 1,464,550 new cases and 487,993 deaths across the world in 2020 and 51,127 new cases in the United States in 2022. A key therapy for these cancers involves radiation therapy, either as sole therapy for early-stage tumors or in combination with surgery or chemotherapy for advanced stage disease. Unfortunately, numerous barriers exist to accessing care for patients requiring radiation. Rural areas face higher cancer and risk factor incidence and mortality rates compared to urban areas, while facing unique challenges (lower educational attainment, difficulties with transportation). In this abstract we explore racial trends and disparities in radiotherapy utilization for oral cavity and pharyngeal cancers across the U.S. Methods: We conducted a population-based cohort study of radiotherapy utilization across racial groups and rural-urban residence over the period 2013-2022. We queried the National Cancer Institute Surveillance, Epidemiology and End Results Program (SEER) for diagnoses of head and neck cancer (Oral Cavity and Pharynx, based on ICD-O-3 sites). Using year of diagnosis as a continuous variable, radiotherapy utilization was modeled as a binomial outcome (received vs did not receive). Multivariable logistic regression was performed to evaluate association between radiotherapy utilization and race, rural-urban residence, and year of diagnosis. Interaction terms were introduced to evaluate effect modification by geography. The reference cohort was Non-Hispanic White. Results: A total of 187,457 Oral cavity and Pharyngeal cancers were included, of which 113,624 utilized radiation therapy while 73,833 did not. 162,717 were urban and 24,740 were rural residents. Radiotherapy utilization declined significantly over time from 2013 to 2022 (-0.7% per annum, OR 0.99 per year, p<0.001). Rural residence was independently associated with lower odds of radiotherapy utilization (OR 0.96, p<0.05). Non-Hispanic Black patients had higher odds of utilization (OR 1.19, P<0.001). While no significant differences were observed for Non-Hispanic Asian/Pacific Islander or American Native/Alaskan patients, significant effect modification by geography was seen for Hispanic patients in rural areas, indicating lower radiotherapy utilization (OR 0.82, p = 0.024). Conclusions: Radiotherapy utilization remains low in rural areas with a concerning declining trend overall. Hispanic race demonstrates geography-specific disparity between rural and urban populations, indicating possible unique barriers to care. While Non-Hispanic Black patients demonstrated significantly higher odds of radiotherapy receipt, non-significant trends towards attenuation were noted, with a significant utilization decline for Non-Hispanic Native American/Alaskan patients indicating worsening disparity over this period.