Comparing the distribution of Hodgkin lymphoma subtypes and survival outcomes between Latin American and US patients

• The distribution of HL subtypes in Latin America may differ from those in the United States

• Despite more frequent adverse clinical features in Latin American patients, survival outcomes are comparable to those in the United States

The lack of lymphoma registries in Latin America limits our understanding of epidemiology and outcomes compared to other countries. We compared the distribution of classical Hodgkin lymphoma (HL) subtypes and overall survival (OS) in Latin American patients to those in the United States (US). We conducted a retrospective cohort study among newly diagnosed adults (aged ≥16) during 2010-2020. Hospital-based data for Latin American patients (n=818) was compared with data from a US population-based registry (n=18,615). Survival analyses were restricted to patients who received therapy, and a propensity match was performed between Latin American and US patients, considering race and ethnicity. Latin American patients had the highest percentage of mixed cellularity HL (26% vs. 13-19% in other US race and ethnicity subgroups, p<0.001). Mixed cellularity was significantly higher in Peru (47%) and Cuba (46%). With a median follow-up of 63 months in the matched cohort, the 5-year OS was comparable between Latin American and all US patients (87% vs. 87%, p=0.960). Outcomes were consistent in subgroup analyses, except for lower OS among Latin American patients aged 15-39 (92% vs. 95%, p=0.030). Latin American patients likely exhibit a distinct distribution of HL subtypes, and outcomes were generally comparable to those of US patients, although findings need validation. Our findings suggest an opportunity to investigate further etiologic factors for HL development and the differential impact of healthcare and social determinants of health factors on survivorship outcomes to improve the survival of patients with HL globally.