Abstract PO-214: Cancer disparities and African American representation in clinical trials involving Accelerated Partial Breast Irradiation Therapy
Authors: Kakadiaris Ev , Lue Brian K , Gu Sherry , Tyes Jonathan C. , Alluri Prasanna 
Published: January 2022

Background Radiation therapy is a critical component in the multi-disciplinary care of many breast cancer patients, but traditionally, has necessitated daily treatment visits over several weeks. Accelerated partial breast irradiation (APBI) in appropriately selected patients affords clinical outcomes that rival those achieved with conventionally fractionated whole-breast radiation. In addition to exposing a smaller volume of breast to radiation, APBI also allows reduction in total number of radiation treatment fractions to 1-10. This regimen thus stands to particularly benefit minorities such as Black American patients, who suffer disproportionately from high rates of economic burden in the form of absence from work, lost wages, and transportation costs related to prolonged cancer treatments. Yet, Black Americans have been traditionally underrepresented in clinical trials, threatening the generalizability of new treatments like APBI. In this study, we evaluated the racial makeup of clinical trials evaluating ABPI and the inclusion of Black Americans in these studies. Methods We retrospectively reviewed all published manuscripts involving accelerated partial breast irradiation therapy and analyzed the demographics of their study populations. Studies reported from centers outside the United States were excluded. When race reporting was not available in the published results, this information, where available, was obtained through the NIH Clinical trials registry. Results A total of 130 APBI trials were identified by PubMed search. Out of these, 80 studies were based in the United States. A total of 20 studies investigating APBI provided demographics data, comprising 1735 total patients. Of these, 1488 patients were White (85.7%), 124 were Black (7.1%), 67 were Hispanic (3.9%), and 46 were Asian (2.7%), and 10 patients were classified as multiple or unknown (0.6%). This percentage is lower than the 2019 US Census estimate of 13.4% Black Americans. We compared these results to two APBI trials conducted at our institution investigating 5-fraction and single fraction APBI regimens. Out of a total of 104 patients treated, 17 patients (16.3%) were Black. The higher proportion of Black Americans in our trials is likely due to a unique partnership between Parkland Hospital, a county Hospital that serves a high proportion of minority patients, and UT Southwestern Medical Center, which provides access to technologically sophisticated treatments such as APBI. Conclusion Despite APBI being uniquely positioned to provide increased benefits to racial minorities, Black Americans are underrepresented in clinical trials evaluating APBI, mirroring the broader national trend in all clinical trials. Based on our institutional experience, partnership between academic medical centers, which often have access to novel treatment regimens and county hospitals, which serve a large proportion of minority patients, is needed to reduce racial disparities in clinical trial participation and to eventually narrow and eliminate the racial health disparity gap.

Citation Format: Ev Kakadiaris, Brian K Lue, Sherry Gu, Jonathan C. Tyes, Prasanna Alluri. Cancer disparities and African American representation in clinical trials involving Accelerated Partial Breast Irradiation Therapy [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-214.