Trends in relative survival of Diffuse large B‐cell lymphoma in Sweden in the era of targeted and cellular therapies

Introduction: Most patients diagnosed with diffuse large B-cell lymphoma (DLBCL) are cured with primary immunochemotherapy, but about one in four experience relapsed/refractory (R/R) disease with worsened outcome. In recent years, new targeted and cellular treatments are becoming available in trials or clinical routine primarily in the R/R setting. However, only a fraction of R/R DLBCL patients are offered these new treatments. We aimed to assess the impact of new treatment options on trends in survival among all patients with DLBCL in Sweden. Methods: We identified all patients diagnosed with DLBCL in the Swedish Lymphoma Register (SLR) 2007–2021, and followed through 31 December 2022. Patients with primary CNS, mediastinal B-cell or transformed low-grade lymphoma were excluded. SLR holds data on age, sex, performance status, stage and lactate dehydrogenase at diagnosis, enabling calculation of the age-adjusted International Prognostic Index (aaIPI) score. We estimated overall (OS) and relative survival (RS) by calendar year of diagnosis in three-year periods. Two-year RS was estimated with the Pohar-Perme method adjusting for age, sex, diagnosis year and aaIPI. Differences in RS were evaluated using the log-rank type test proposed by Graffeo et al. Results: Overall, 8,808 patients were diagnosed with DLBCL during the study period (median age 72 years, range 18–105, 57% male). In the full cohort, 2-year OS was 66% among patients diagnosed 2007–2009, increasing to 71% for 2019–2021 (poverall < 0.001, Figure 1A). Improvements in 2-year RS were noted across all groups by age, sex and aaIPI score. However, by age, improvements were primarily observed among patients aged 60–69 and 80+ years (Figure 1B). By risk group, improvements were mainly noted among young high-risk patients (aaIPI 2–3, age <70 years) and among older patients (70+ years) independently of aaIPI (Figure 1C). In young high-risk patients, the 2-year RS increased from 71% among patients diagnosed 2007–2009, to 83% among patients diagnosed 2019–2021 (poverall < 0.001). The research was funded by: Swedish Cancer Society Keywords: Aggressive B-cell non-Hodgkin lymphoma, Cellular therapies No conflicts of interests pertinent to the abstract.