Distribution of non-Hodgkin lymphomas across US: Are Hispanics any different from non-Hispanics?

Abstract

e18619 Background: Non-Hodgkin lymphoma (NHL) encompasses various subtypes that differ in incidence, etiology, clinical features, and survival. NHL subtypes can be divided into B-cell and T-cell lymphomas, when classifying them based on cell of origin. The distribution of NHL subtypes has been known to variate between geographic locations, and always results are reported without classifying them among ethnicities. Hispanics are by now, the largest ethnic minority in US, according to the latest 2020 US Census, and it is of utmost importance to understand variations related to ethnicity. This is to our knowledge, the largest retrospective study comparing NHL frequency of subtypes in Hispanics vs Non-Hispanics. Methods: Data were analyzed on NHL patients in the US and reported to the Surveillance, Epidemiology, and End Results (SEER) 18 database between 2000 and 2018. SEER 18 contains the most comprehensive population-based cancer information in the US, covering approximately 27% of the US population and up to 36% of HI alone. Racial groups analyzed included NH whites and HI whites. Results: There were 366516 patients diagnosed with NHL over the 8-year study period included in our study. Most of these patients belong to the B-cell NHL type, comprising 91% of the group. The distribution of the major subtypes of NHL is shown in the pie charts. We noted differences in the distribution of major NHL subtypes among NH and H. Among the B-Cell NHL subtypes, Hispanics had higher proportions of DLBCL (42% vs. 31%), FL (19% vs. 17%), and Burkitt lymphoma (4% vs. 2%) than NH. On the contrary, a significant difference was found, with a higher presence of CLL/SLL in NH, which was seen in 31% vs. 15% in H. Within the T-Cell NHL subtypes, compared with non-Hispanics, Hispanics had higher proportions of NK/T cell lymphoma (11% vs. 3%) and anaplastic large cell lymphoma (15 vs. 12%) but a lower proportion of mycosis (26% vs. 30) in NH and cutaneous T-cell lymphoma (9% vs. 13%). The rest of the subtypes showed to have similar proportion rates. Conclusions: In conclusion, our study shows evidence of a significant difference in subtype distribution between NH and H patients. The involvement of a complex process in developing NHL and the etiologic heterogeneity among subtypes has been previously described. These differences in subtype distribution across races may be due to geographic location, genetic variants, occupational exposures, infectious conditions, family history, and socioeconomic status. Analyzing and comparing multiple cancer subtypes can provide critical clues for future epidemiological investigations to improve care among our minorities. Due to the growing Hispanic population in the US, it is significantly vital to represent the differences in subtype presentation graphically.