The impact of marginalization on diffuse large B-cell lymphoma overall survival: a retrospective cohort study

The aim of this study was to describe the impact of marginalization on DLBCL overall survival (OS) within the Canadian setting. We conducted a population-based retrospective cohort study of adult patients with newly diagnosed DLBCL in Ontario between 1 January 2005 and 31 December 2017 receiving a rituximab-containing chemotherapy regimen with curative intent followed until 1 March 2020. Our primary exposure of interest was the Ontario Marginalization Index (ON-Marg). The primary outcome was 2-year OS, accounting for patient age, sex, cancer characteristics, comorbidity burden, and rural dwelling status. While two-year overall survival was inferior for individuals in the most deprived marginalization quintile (70.4% Q5 vs. 76.0% Q1), after adjustment for relevant covariates neither the composite ON-Marg nor any of its dimensions had a significant effect. Within the Canadian context, among patients who receive chemotherapy, marginalization may not have a significant association with overall survival when accounting for key patient covariates, lending support for preserved outcomes.