Representation of Minorities in Therapeutic Clinical Trials – a 15-Year Review of Lymphoma Cooperative Group Studies (Alliance A152123)

Introduction: Health disparities negatively impact outcomes of patients (pts) with hematologic malignancies. Limited retrospective data correlating health disparities with lymphoma outcomes prohibit proper identification of reversible causes and elaboration of potential interventions. We present data from a coordinated effort between the National Clinical Trials Network (NCTN) cooperative groups (Alliance for Clinical Trials in Oncology [Alliance], Eastern Cooperative Oncology Group [ECOG], and the Southwest Oncology Group [SWOG]) to catalog the racial, ethnic, and socioeconomic characteristics of pts with lymphoma to better understand the quality of data collected, analyze selected health disparity indicators, and develop a prospective data collection tool.

Methods: We conducted a retrospective analysis of demographic data from pts with lymphoma enrolled on 32 cooperative group therapeutic trials between 2005 and 2020. Special focus was placed on data regarding race, ethnicity, and proxies that help identify socioeconomic status (health insurance, residential zip code, Social Deprivation Index [SDI]). These were evaluated in relation to histology-based metrics from the Surveillance, Epidemiology, and End Results Program (SEER) Program with reported data through 2022. Here, our focus is to characterize baseline demographic and disparities data on the collection of these 32 NCTN lymphoma trials.

Results: A total of 3,897 pts were included, with 3,406 non-Hodgkin lymphoma (87.4%) – 1,644 diffuse large B-cell (DLBCL, 48.3%), 905 follicular (26.6%), 669 mantle cell (19.6%), 113 primary central nervous system (3.3%), 75 T-cell (2.2%) – and 491 Hodgkin lymphoma (12.6%). Age at registration was available for 3,891 pts with median age 57.1 years (range: 18-92). The majority of patients were male (58.8%; one pt missing biological sex data). Race data were available for all but one patient, where most pts were white (W, 86.6%), followed by 246 African American (AA, 6.3%), 99 Asian (A, 2.5%), 13 American Indian or Alaska Native (AI, 0.3%), 8 Native Hawaiian or Pacific Islander (PI, 0.2%), 11 with more than 1 race reported (0.3%), and 145 with unknown/not reported race. Ethnicity data were unknown for 327 pts (8.4%) with 179 Hispanic or Latino (Hisp, 4.6%). Combined race/ethnicity data showed 3,010 non-Hisp white (NHW, 77.2%) and 219 non-Hisp black (NHB, 5.6%). For comparison, in the SEER database, 84.7% of all lymphoma cases were W, with 8.6% AA, 5.2% A/PI, 0.4% AI, and 1.1% unknown race, and with 13.9% of pts reported as Hisp. When focusing on the 804 pts enrolled on Alliance CALGB 50303 and ECOG-ACRIN 1412 studies, two randomized DLBCL studies, there was a more proportional representation of W and AA pts with DLBCL - 82.1% and 9.8% compared 84.6% and 7.7%, respectively, at SEER database, with 5.3% Hisp (with another 5.3% unknown) compared to 14.9% at SEER.

Insurance information was missing in 113 pts. Of the remainder, 2,102 pts had private insurance only (55.6%), 549 with a mix of private and public (14.5%), 701 public only (18.5%, including 11.4% Medicare, 4.5% Medicaid, 0.8% both), and 166 self-pay (4.4%). Year-matched SDI score was available in 2,885 pts, where higher SDI scores = higher social deprivation. The total mean SDI score for the overall cohort was 42.5 with significant differences observed based on race/ethnicity and insurance type. Specifically, NHW were from less deprived areas (mean SDI=38.8) than NHB (66.4) or Hisp (65.5) (p<0.0001). Those without insurance (mean SDI=52.6) or only public insurance (48.9) were located in areas associated with greater deprivation compared to pts with private (40.1) or public+private (38.8) insurance (p<0.0001).

Conclusion: To our knowledge, this is the largest retrospective catalog of racial, ethnic, and socioeconomic characteristics of pts with lymphoma enrolled on cooperative group therapeutic trials. The scope of NCTN cooperative group lymphoma studies provides a unique opportunity to assess novel therapeutic outcomes for patients representing racial, ethnic and socioeconomic subgroups with both common and rare lymphoma subtypes. From this resource, additional analyses on relationships between SDI, race/ethnicity, insurance coverage, disease subtype, and temporal trends will be presented.

Support: U10CA180821, U10CA180882, UG1CA189823