Abstract PO-115: Defining radiation treatment quality disparities in the COVID-19 Era
Authors: Gaudio Elizabeth C. , Ammar Nariman , Wakefield Daniel V , Pisu Maria , Shaban-Nejad Arash , Schwartz David L 
Published: January 2022

Background: Cancer outcomes in the U.S. Mid-South (West Tennessee, Mississippi Delta, Eastern Arkansas) are poor, and have potentially been exacerbated by the COVID-19 pandemic. Unplanned interruption of daily radiation therapy (RT) is associated with socially vulnerable populations and inferior survival outcomes. Radiation treatment interruption (RTI) rates during the pandemic remain unreported. The purpose of this work was to quantify our local RTI rates before and after the onset of the pandemic, and to characterize social risk factors predictive for interruption during COVID-19. Methods: Demographic, clinical and treatment information were retrospectively analyzed for patients receiving RT with curative or palliative intent at a single academic center between January 2015 and December 2020. Minor RTI was defined as a delay in 2 or more scheduled radiation treatments. Major RTI was defined as greater than or equal to 5 (i.e. one week or greater) unplanned RT appointment cancellations. Patient insurance status was considered “At-Risk” if they had Medicaid or no insurance. Patient predicted income (PPI) was categorized as low, middle or high using 2020 US Census data for patient's home address zip code. RTI was compared across insurance type, race, PPI and whether they started RT before or after the onset of COVID-19 (March 15, 2020). Results: 2176 out of a total 2731 patients treated at our academic center were analyzable; 1913 were treated before and 263 were treated after COVID-19 onset. On-treatment patient census fell by &gt;50% following onset of COVID-19, with protracted, incomplete recovery through 2020. 829 (38.3%) patients experienced minor RTI, while 381 (17.5%) of patients experienced major RTI. All RTI rates increased following onset of COVID-19 relative to pre-pandemic (43.0% vs. 14.0%, P &lt;0.001 and 74.1% vs. 33.1%, P &lt; 0.001, for major and minor RTI, respectively). Compared to baseline disparities, increased major, but not minor, RTI rates were seen in African American compared to White patients during the pandemic (48.4% vs. 38.4%, P&lt;0.05). Additionally, patients with Medicaid or no insurance experienced increased rate in major RTI compared to patients with commercial insurance in contrast to pre-pandemic differences (56.1% vs. 32.0%, P&lt;0.05) Conclusion: We have previously shown minority and low socioeconomic patient populations to be at risk for RT quality shortfalls. The COVID-19 pandemic exacerbated pre-existing RTI rates at our academic center, and disproportionately impacted socially vulnerable groups. Our findings are limited to a single institution which saw protracted reductions in patient referrals during the early pandemic. This may represent a consequence of upstream barriers to care, the most severe form of treatment “interruption”. To improve generalizability and robustness of our findings, this study should be reproduced broadly at other centers. Future directions will focus on identification of candidate mechanisms responsible for elevated RTI observed in vulnerable populations during the pandemic and beyond.

Citation Format: Elizabeth C. Gaudio, Nariman Ammar, Daniel V Wakefield, Maria Pisu, Arash Shaban-Nejad, David L Schwartz. Defining radiation treatment quality disparities in the COVID-19 Era [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-115.