Comparison of Mortality Rates Between Patients With Diffuse Large B Cell Lymphoma Surviving 5 Years After Initial Diagnosis and a Matched General Population Cohort

Abstract

Aim: To determine whether mortality for patients with diffuse large B-cell lymphoma who survived 5 years (DLBCL5ys) returns thereafter to general population levels. Methods: This population-based cohort study included Danish residents between January 1, 2000, and December 31, 2023. Information on diagnoses, comorbidities, and vital status came from Danish health and administrative registries. Analyses included 4164 DLBCL5yr patients—55% of incident patients—and 41,640 individuals from the general population matched 10:1 by exact birth year, sex, and the calendar year of achieving DLBCL5yr status. We used Cox proportional hazards models to compute matched mortality hazard ratios (HRs) and 95% confidence intervals (CIs) and controlled for comorbidities by adding Charlson comorbidity index scores to our models. Results: Mortality rates were elevated for DLBCL5yr patients soon after their 5-year survival date. The absolute difference in mortality was 20 deaths per 1000 person-years, and the HR adjusted for comorbidities was 1.5 (95% CI 1.4–1.6). Mortality was elevated similarly for men and women. The elevated mortality for DLBCL5yr patients varied in magnitude by age, calendar period, and comorbidity burden, and included excess mortality from DLBCL, cancers other than lymphoma, and respiratory diseases. Conclusions: We found that mortality for DLBCL5yr patients did not return to general population levels.