Abstract 4823: Survival outcomes similar in T-cell/histiocyte-rich large B-cell lymphoma between Hispanics and non-Hispanics within the United States
Authors: Mines Ian , Urueta-Portillo Daniela , Liu Qianqian , Michalek Joel , Duque Adolfo E. Diaz 
Published: March 2024

Background: T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a rare variant of large B-cell lymphoma with features that overlap with Nodular lymphocyte-predominate Hodgkin lymphoma (NLPHL). (Blood PMID: 32871584, PLoS One PMID: 24244368,Haematologica PMID: 20207840). Unlike NLPHL, which has a good prognosis. THRLBCL’s prognosis is worse (Leuk Lymphoma PMID: 31287335). Given its rarity and difficulty to diagnose, limited studies explore prognostic factors for it. This study aims to explore clinical, demographic, and survival outcomes differ in Hispanic (HI) versus non-Hispanic (NH) patients with THRLBCL in the United States (US).

Methods: Data were analyzed on THRLBCL patients in the US and reported to the National Cancer Database (NCDB) between 2004 and 2019. Demographic and treatment characteristics were compared between ethnic groups. Kaplan-Meier and Cox regression analyses compared OS between HI and NH. Multivariate analysis and propensity score matching was performed with adjustment for age, stage, co-morbidity score, insurance status, type of facility, and great circle distance.

Results: Of 1252 THRLBCL patients, 7% were HI and 93% NH. 67% of HI were male, compared to 68% of NHHI pts were younger at diagnosis 55 vs 57 (p=0.471); the majority of HI and NH were &lt;65, 64% and 66% respectively (p=0.574)Most of HI and NH were white (88% vs 74%). When examining stage, most of HI and NH were stage (IV) (50% vs 57%) (p=0.600)Regarding insurance type, Government-sponsored was the most prevalent in HI (52%), while private insurance was most prevalent for NH (51%) (p=0.001). The most non-Insured group was HI (11% vs 3%).Regarding Census Median Income (2008-2012), the most prevalent bracket (39.5%) for HI was $48,000 - $62,999, and for NH (31%) $&gt;63,000. Charlson-Deyo Score (comorbidities score), HI had a 10% =/&gt; 2 score, vs NH 7%. Regarding treatment facility type Academic/Research Programs were the most prevalent for HI (44%) and NH (38%).The median distance in miles between the patient’s residence and the hospital that reported the case (Great Circle Distance), HI lived at a median of 10 miles, vs NH at a median of 11 miles. On survival analysis, the survival probability at 2, 5, and 10 years of HI vs NH were 83% vs 83%, 77% vs 75%, and 69% vs 62%. The median survival time (MS) was not reached for HI or NH. There was no overall survival difference (OS) between HI/NH (p=0.8). Independently, on multivariate analysis, ethnicity was not associated with worse OS (HR 1.2, CI 0.67-2.17, p=0.54).

Conclusion: The MS and OS between HI and NH with THRLBCL within the US were similar. However, due to the rarity of THRLBCL, the size of both populations was small, which reduces the confidence that there are no

differences in the outcomes of these two populations. Because of this, more data is needed to evaluate further the clinical and socioeconomic factors that play a role in the survival outcomes of THRLBCL.

Citation Format: Ian Mines, Daniela Urueta-Portillo, Qianqian Liu, Joel Michalek, Adolfo E. Diaz Duque. Survival outcomes similar in T-cell/histiocyte-rich large B-cell lymphoma between Hispanics and non-Hispanics within the United States [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 4823.