A nationwide population based primary CNS lymphoma (PCNSL) analysis: Do Hispanics have better outcomes?

Abstract

10560 Background: Over the last decade, overall survival (OS) of PCNSL patients has increased from 12.5 months to 26 months (N. Oncol, PMID 30418592). One study examined the incidence of PCNSL in the Hispanic (HI) population in Texas (Cureus, PMID: 33042676), but a national study is needed to understand ethnic disparities, as many HI face barriers to health care access (Natl Cance Inst Monogr, PMIDL 8562207). This study aims to understand demographics, treatment patterns, and outcomes of HI and Non-Hispanic (NH) patients with PCNSL nationally. Methods: Data analyzed on PCNSL patients in the United States (US) was reported to the Surveillance, Epidemiology, End Results (SEER) 18 database between 2000 and 2018. Racial groups analyzed included NH whites, HI whites, Blacks, and Asian/Pacific Islanders (PI). Patient characteristics, age-adjusted incidence rate, and survival rate were compared across ethnic groups (HI vs. NH). Stratification by age, gender, and stage at diagnosis was considered. Data was stratified using Kaplan-Meier and Cox regression analyses to compare OS between HI and NH. Multivariate analysis and propensity score matching was performed with adjustment for age, stage, and B-symptoms. Results: Of 5819 PCNSL patients, 15% were HI, and 85% NH. 57% were male compared to 51% of NH. As compared to NH at diagnosis, HI patients were younger, 59 years vs. 66 years(y) (p<0.001); the majority of HI (42%) were diagnosed in the age bracket of 60-80y (p<0.001). Approximately 30% of HI were diagnosed in 2015-2018, while most of NH (29%) were diagnosed in 2010-2014 (p=0.054). With 52% of HI being diagnosed at <60y, only 32% in NH. As for race, most of HI and NH were White (97% vs. 79%), followed by Black (1% vs. 8%). On survival analysis, the survival probability at 2, 5, and 10y of HI vs. NH were (0.507 vs. 0.441), (0.395 vs. 0.322), and (0.237 vs. 0.225), respectively. The median survival time was 2.1y for HI vs. 1.2y for NH. There was an OS difference favoring HI (p=0.0009). On multivariate analysis, when adjusted for age, patients with PCNSL between 60-80y and above have 3.4 times more likely to die from disease after diagnosis with HR 3.4 (95% CI:2.9-4) and 1.7 (95% CI: 1.6-1.9). Conclusions: Our study demonstrates statistically longer median survival and OS favoring the HI population. The younger age of diagnosis in HI patients could be a factor in their survival probability for PCNSL, given that both HI and NH received similar treatment and had a similar staging. However, additional studies would be needed to validate this observation and determine other biological or socioeconomic factors that may play a role. [Table: see text]