ABCL-078: Clinicopathological Features of Double-Hit and Double-Expressor Lymphomas in Hispanics Versus Non-Hispanics in Central California

Abstract

Context: Double-hit lymphoma (DHL) and double-expressor lymphoma (DEL) are subtypes of diffuse large B-cell lymphoma (DLBCL) with limited studies investigating if any variations within ethnic groups exist. Objective: To determine if differences in incidence and outcome between Hispanics and non-Hispanics in DHL and DEL exist. Design: Retrospective, single-center study analyzing patients diagnosed between the years 2013-2017. Source: Community Medical Centers Cancer Registry in Fresno, CA. Setting: Academic-affiliated community hospital. Patients or other participants: Patients greater than 18 years old diagnosed with DHL or DEL. Primary CNS lymphoma excluded. Main outcome measures: Incidence, 2-year progression free survival (PFS), 2-year overall survival (OS) in Hispanics vs non-Hispanics Results: Among 168 patients with DLBCL, 24 patients met criteria (n=10 DHL, n=14 DEL). In DHL, median age 62.5 (range 55-76), germinal center (GC) origin in 7 (70%), stage IV disease in 9 (90%), high-intermediate/high international prognostic score (IPI) in 9 (90%), 5 were Hispanics (50%). 8 patients (80%) underwent intensive induction therapy (REPOCH, RICE, R HyperCVAD). 5 achieved complete remission (CR). Incidence was 11.2 per 100 new cases of DLBCL in Hispanics versus 4.2 in non-Hispanics with an odds ratio of 2.76 (p=0.14). 2-year PFS 80% and 2-year OS 80% in Hispanics versus 40% and 40% (p=0.42), respectively, in non-Hispanics. In DEL, median age 70 (range 47-91), GC origin in 6 (42.9%), stage IV disease in 7 (50%), high-intermediate/high IPI in 10 (71.4%), 3 were Hispanics (31.4%). 6 patients (42.9%) received REPOCH with 5 achieving CR. 6 patients received RCHOP, 2 of them only achieved CR. In Hispanics, the incidence was 6.6 versus 9.5 in non-Hispanics with odds ratio of 0.682 (p=0.76). 2-year PFS was 67% and 2-year OS was 67% in Hispanics versus 45.4% and 54.5% (p=0.38) in non-Hispanics. Conclusion: In our study population, there is a trend towards increased incidence rate of DHL in Hispanics compared to non-Hispanics. 2-year PFS and OS in Hispanics in both DHL and DEL subtypes were numerically higher but did not reach statistical significance due to small sample size. Further evaluation with larger sample size is warranted.