Abstract D085: Differences in the use of proton beam therapy among patients diagnosed with American Society for Radiation Oncology Group 1 proton beam therapy indication cancer types in the United States

Purpose: To examine the extent of racial/ethnic and geographic differences in the use of proton beam therapy (PBT) among newly diagnosed cancer patients in the United States. Methods: We included all patients diagnosed from 2009 to 2016 with invasive single or first primary cancer categorized as Group 1 indication (recommended) for PBT by the American Society for Radiation Oncology. We conducted descriptive and multivariable multinomial logistic regression analyses to assess patient and facility characteristics associated with receipt of PBT. Results: Of the total 246,932 patients diagnosed with Group 1 indication cancer types, 0.6% received PBT. PBT use was lower in non-Hispanic (NH) blacks compared with NH whites (0.3% vs 0.6%). Patients who were older, uninsured, with low median income, higher comorbidity score, treated at low volume or community programs or at facilities located in the south, and residing in rural areas had the lowest PBT use. There was a 46% relative difference in PBT use between NH blacks and NH whites, with marked variation by geographic region of facility. NH black had 37% lower odds of receiving PBT compared with NH whites (odds ratio, 0.63; 95% confidence interval, 0.50-0.79), which became nonsignificant after accounting for difference in cancer type. Further, minority race/ethnicity, older age, high comorbidity score, uninsurance/non-private insurance, treatment out of NCI-designated center, and treatment out of facilities in the northeast region were significantly associated with lower odds of PBT use versus no radiation treatment. Conclusions: Despite very low overall PBT use in the United States, there were marked differences in PBT use among patients diagnosed with Group 1 indication cancer types by race/ethnicity and geographic region of treatment facility.

Citation Format: Helmneh M. Sineshaw, K. Robin Yabroff, Ahmedin Jemal, Leticia M. Nogueira, Jason A. Efstathiou. Differences in the use of proton beam therapy among patients diagnosed with American Society for Radiation Oncology Group 1 proton beam therapy indication cancer types in the United States [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D085.