Outcomes and factors influencing survival in patients with diffuse large B-cell lymphoma: a population-based analysis

Given the rapidly evolving treatment landscape for diffuse large B-cell lymphoma (DLBCL), we performed a contemporary analysis of survival outcomes in patients aged ≥18 years with DLBCL at the population level using linked administrative data sets in Ontario, Canada (ICES). Among 8675 patients (median age, 67 years; 44% female) treated with frontline rituximab-based therapy, 1675 (19%) were treated with second-line therapy (2L). The 2-year and 5-year overall survival (OS) from 2L were 33% and 26%, respectively. Univariate analysis demonstrated that curative-intent therapy (autologous stem cell transplantation [ASCT]) (58% of patients) was associated with better OS than palliative radiotherapy (hazard ratio [HR], 0.56; <i>P</i> < .0001). Patients aged ≥60 years showed inferior OS than those aged <60 years (age 60-69 years: HR, 1.35; <i>P</i> =.0002; aged 70-79 years: HR, 1.64; <i>P</i> < .0001; age ≥80 years: HR, 2.08; <i>P</i> < .0001). In addition, early relapse was associated with worse outcomes than relapses occurring after 2 years (<3 months: HR, 1.45; <i>P</i> =.0002; 3-6 months: HR, 1.51; <i>P</i> =.0001; 6-12 months: HR, 1.88; <i>P</i> < .0001). Multivariable analysis confirmed these associations while accounting for lactate dehydrogenase, comorbidity burden, frailty, and income. Exploratory analysis indicated that third-line chimeric antigen receptor T-cell (CAR-T) therapy was associated with improved outcomes compared to a historical cohort of patients treated with palliative therapy before 2020 (2-year OS 56% vs 21%). This population-based analysis suggests that curative-intent therapy (ASCT and CAR-T) is associated with improved OS over conventional treatment approaches. The outcomes presented here provide benchmarks for future analyses aimed at assessing the effects of novel treatments in the 2L on outcomes.