Abstract 4857: Contemporary hospital-based study examining demographics, treatment patterns and survival outcomes of primary effusion lymphoma in the United States, with a specific emphasis on Hispanics
Authors: Avila Sergio A. Vallejo , Michalek Joel , Liu Qianquian , Duque Adolfo E. Diaz 
Published: March 2024

Background: Primary effusion lymphoma (PEL) is a rare and aggressive non-Hodgkin lymphoma associated with HIV and human herpesvirus 8 (HHV-8). (Blood PMID: 8695812). Without treatment, patients typically survive only two to three months (Oncol Res Treat PMID: 28253516) Limited research has been conducted on PEL, particularly in minorities in the United States. Limited research, especially in minority populations (Blood PMID: 30154110), has prompted a nationwide study comparing demographics, clinical characteristics, treatment patterns, and survival outcomes between Hispanic (HI) and Non-Hispanic (NH) PEL patients.

Methods: Data on PEL patients from the National Cancer Database (NCDB) between 2004 and 2019 were analyzed in the US. Demographics and treatment characteristics were compared across ethnic groups. Kaplan-Meier and Cox regression analyses were used to compare overall survival (OS) between HI and NH populations. Multivariate analysis and propensity score matching were conducted, adjusting for age, stage, co-morbidity score, insurance status, type of facility, and great circle distance.

Results: Of 459 PEL patients, 18% were HI, and 79% were NH. Both groups had mostly male patients (87% vs. 86%). HI patients were younger at diagnosis (mean 49 years vs. 57 years, p=0.163). Diagnoses were mostly from 2014-2019, and the majority were white (87% vs. 69%). Government-sponsored insurance was more prevalent in both groups (62% vs. 66%). HI had a higher percentage of uninsured individuals (8% vs. 5% NH) (p-value=0.01). The median income bracket was over $46,000 for both cohorts, HI 34% and NH 37%. Advanced comorbidities were similar between HI 50% and NH 43% based on Charlson-Deyo Score. The survival probabilities at 2, 5, and 10 years for HI vs NH were (40% vs 40%), (34% vs 289%), and (34% vs 24%), respectively. The median survival time (MS) was 0.8 years for HI and 0.9 years for NH. There was no overall survival (OS) difference (p-value=0.51). On multivariate analysis, there were no independent variables associated with better or worse OS. The propensity-matched analysis showed no MS difference between HI and NH (0.80 vs 0.71 years).

Conclusion: This hospital-based analysis confirmed low survival rates and revealed no statistical differences in MS or OS among HI and NH individuals with PEL. Interestingly, the disease was more prevalent in high-income subjects in both cohorts, despite HI individuals having lower insurance rates. A better understanding of intrinsic disease characteristics and biological variables can offer valuable insights into how to unveil potential targets of better and hopefully meaningful therapies that could improve survival outcomes.

Citation Format: Sergio A. Vallejo Avila, Joel Michalek, Qianquian Liu, Adolfo E. Diaz Duque. Contemporary hospital-based study examining demographics, treatment patterns and survival outcomes of primary effusion lymphoma in the United States, with a specific emphasis on Hispanics [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 4857.