Abstract 4845: Evaluating racial disparities in immune checkpoint inhibitor survival and autoimmunity
Authors: Nunes Kathryn L. , Llerena Pablo , Kaki Praneet , Mandloi Shreya , Moroco Annie , Mastrolonardo Eric , Cognetti David M. , Luginbuhl Adam J. , Curry Joseph M. 
Published: March 2024

Introduction: In recent years, immune checkpoint inhibitors (ICI) have revolutionized the landscape of treatment across a variety of cancers. Potential concerns regarding racial disparities in ICI access and therapeutic efficacy have been well documented. Recent studies have indicated improved ICI access and response outcomes in White patients compared to minority groups with head and neck cancer (HNC) and melanoma patients. In contrast, patients diagnosed with lung cancer have been mixed, with some research suggesting black patients may fare better with ICI therapy. Existing literature is largely limited to retrospective studies with small population sizes, and lacks comparisons of racial disparities across malignancies. We aim to describe and compare racial inequities in ICI outcomes in HNC, melanoma, and lung cancer.

Methods: The TriNetX US Collaborative Network database was queried for patients &gt;18 years-old with a diagnosis of head and neck cancer, melanoma or lung cancer that were treated with ICIs. Malignancy cohorts were defined by race: non-Hispanic White (NHW) and Black. Race cohorts were 1:1 propensity score matched (PSM) for comorbidities, oncologic stage, and chemoradiation treatment. Demographic differences in cohorts were evaluated prior to matching. Following PSM, overall survival and rates of autoimmunity were assessed at 5 years.

Results: 19,443 NHW and 2,827 Black patients treated with ICI were identified. At a baseline, the Black patient cohorts had significantly higher rates of comorbidies (p&lt;0.02). Across all malignancies, the geographic distribution of NHW patients was more equally distributed compared to Black patients (majority south). With PSM, black HNC patients had significantly lower survival rates compared to NHW [HR: 1.4 (1.2, 1.6), p=0.0002]. In melanoma, the same trend was present, though not significant [HR: 1.3 (0.95, 1.7), p=0.1]. In contrast, in lung cancer, Black patients had significantly higher survival rates compared to NHW patients [HR 0.78 (0.70, 0.86), p&lt;0.0001]. In HN and lung cancer, NHW patients had significantly higher rates of autoimmune conditions after ICI therapy compared to Black [OR: 2.0 (1.4,2.8), 1.2 (1.0, 1.4), respectively].

Conclusion: This study represents the most extensive analysis of racial disparities on ICI outcomes across malignancies. This study found that black patients treated with ICIs had decreased survival rates at 5 years compared to NHW patients in HNC and melanoma, but increased survival rate in lung cancer. This disparity persisted following PSM, matching cohorts for comorbidities, oncologic stage and adjuvant therapy. Black patients also had significantly lower rates of autoimmunity in HN and lung cancer. Noted differences in survival may be a reflection of geographic practice differences, access to care and/or socioeconomic status. Further investigation is required to elucidate the underlying etiologies of these trends.

Citation Format: Kathryn L. Nunes, Pablo Llerena, Praneet Kaki, Shreya Mandloi, Annie Moroco, Eric Mastrolonardo, David M. Cognetti, Adam J. Luginbuhl, Joseph M. Curry. Evaluating racial disparities in immune checkpoint inhibitor survival and autoimmunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4845.