Temporal trends in relative survival and excess mortality among US adults with lymphoid malignancies.

BACKGROUND: Lymphoid malignancies comprise a heterogeneous group of diseases with diverse treatment approaches and outcomes. Therapeutic advances have been uneven across subtypes, and contemporary data on temporal changes in mortality remain limited. We assessed trends in survival and excess mortality using US population-based data. METHODS: This retrospective cohort study included patients newly diagnosed with lymphoid malignancies during 2001-2018 from 17 registries of the Surveillance, Epidemiology, and End Results program. We estimated 5-year relative survival and modeled excess mortality using Poisson regression. RESULTS: Five-year relative survival improved and excess mortality decreased over time for precursor lymphoid malignancies, Hodgkin lymphomas, and most mature B-cell lymphomas. Among subtypes with declining excess mortality, average reductions ranged from 6% to 20% per calendar period. The largest declines were observed for lymphocyte-rich Hodgkin lymphoma (20% reduction), followed by B-cell (19% reduction) and T-cell lymphoblastic leukemia/lymphoma (18% reduction). In contrast, excess mortality for certain aggressive mature T-cell lymphomas showed little or no improvement, including adult T-cell leukemia/lymphoma, peripheral T-cell lymphoma not otherwise specified, and angioimmunoblastic T-cell lymphoma. Subgroup analyses suggested more pronounced excess mortality declines among younger adults compared to middle-aged or older adults for several subtypes. CONCLUSION: Most lymphoid malignancies showed improvements in survival and declines in excess mortality over time. However, certain rare and aggressive subtypes exhibited limited or no progress. These findings may reflect overall benefits from advancements in treatment and supportive care, while identifying research priorities for lymphoid subtypes with unmet survival needs.