Abstract 2624: Clinical trial participation in real-world patients with metastatic breast cancer: disparities and barriers
Authors: Tan Ruoding , Wang Rongrong , Abbass Ibrahim , Cassoli Lourenia , Mitchell Edith P. 
Published: July 2021

Abstract
Background: Reducing barriers to patient participation in clinical trials is vitally important to the cancer care community. Using data from a real-world cohort of metastatic breast cancer (mBC) patients (pts), we evaluated how race/ethnicity and other socioeconomic, institutional, and clinical barriers play a role in trial participation.
Methods: Adult females with mBC were selected from Flatiron Health EHR-derived de-identified database (2011- 2020). Clinical trial participation was determined by having “clinical study drug” in any line of therapy. Multivariate logistic regressions were used to assess how various barriers impact trial participation.
Results: In this cohort of 22,220 mBC pts, 1,131 (5.1%) were enrolled in clinical trials and participation rates vary by line of therapy, race/ethnicity, age, insurance, location, and care setting (Table 1). Comparing pts characteristics between enrolled vs. not enrolled, pts ever enrolled were significantly younger (mean age: 59 vs 63), had better performance status (ECOG PS ≥ 2: 3% vs 8%), and less Brain/CNS metastasis (3% vs 6%), more likely to be white (75% vs 61%), lived in the south (55% vs 38%), and had commercial insurance (34% vs 29%), with all p&lt;0.001. Controlling for all SES and clinical characteristics that significantly differ between pts enrolled vs. not enrolled, racial/ethnic minority status remained as a strong predictor for lack of trial participation ([OR(95%CI)]: African-American(AA) [0.5(0.4-0.7)]; Hispanic: [0.6(0.4-0.8)], vs White).
Conclusions: Preliminary results of this study reveal significant demographic and socioeconomic disparities in trial participation among mBC patients. In particular, AA and Hispanic patients were less likely to participate in clinical trials after controlling for other individual- or system-level factors that may impact enrollment. Future efforts to understand the relationship between racial disparity and other well-known barriers are needed.
TABLE 1.Proportion of Patients Enrolled in Clinical Trials (N=22,220)Total, NProportion enrolled in clinical trials, n(%)Line of Therapy1L19,559435 (2.2%)2L12,627336 (2.7%)3L+7,959360 (4.5%)*Age at Diagnosis&lt;6511,356732 (6.4%)*65 - 755,801273 (4.7%)75+5,063126 (2.5%)Race/EthnicityAfrican-American2,39597 (4.1%)Hispanic or Latino1,70251 (3.0%)Asian49420 (4.1%)White13,707851 (6.2%)*Other/Unknown3,922112 (2.9%)Geographic RegionMidwest3,062106 (3.5%)Northeast3,89476 (2.0%)South8,645618 (7.2%)*West3,998174 (4.4%)Insurance at DiagnosisCommercial6,398388 (6.1%)*Medicaid49013 (2.7%)Medicare4,232158 (3.7%)Other or Missing11,100572 (5.2%)Care SettingAcademic1,558137 (8.8%)*Community20,662994 (4.8%)Note: * denotes subgroup of patients with the highest rate of clinical trial participation
Citation Format: Ruoding Tan, Rongrong Wang, Ibrahim Abbass, Lourenia Cassoli, Edith P. Mitchell. Clinical trial participation in real-world patients with metastatic breast cancer: disparities and barriers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2624.