Research Article: Age-stratified survival and competing mortality in adult acute lymphoblastic leukemia and lymphoblastic lymphoma: a population-based competing-risk and restricted mean survival analysis
Abstract:
Survival differences by age are well recognized in adult acute lymphoblastic leukemia/lymphoma (ALL/LBL), but their timing, competing-mortality structure, and behavior across recent diagnosis periods remain less clear.
This retrospective SEER cohort included adults diagnosed during 2010-2023, excluding Burkitt leukemia/lymphoma. We estimated overall survival (OS), 3-year restricted mean survival time (RMST), and cumulative incidence of ALL/LBL-attributable and other/unknown-cause death. Cox, Fine-Gray, spline, and exploratory time-split models assessed age associations.
Among 9,491 patients, 4,618 died: 3,828 deaths were attributed to ALL/LBL and 790 to other or unknown causes. Three-year RMST was 1.89, 2.10, and 2.14 years in 2010-2014, 2015-2019, and 2020-2023, respectively; the recent-period difference was 0.044 years (95% CI -0.016 to 0.104; P = 0.150). Median follow-up in 2020–2023 was 22 months. Compared with age 18–39 years, the adjusted overall-mortality HR for age >=75 years was 6.258 (95% CI 5.627-6.960). Because proportional hazards were violated, this HR should be read as a summary association. The exploratory HR was 8.201 (95% CI 7.224-9.311) during the first year and 3.496 (95% CI 2.885-4.236) thereafter. At 3 years, cumulative incidence in patients aged >=75 years was 70.4% for ALL/LBL-attributable death by registry attribution and 12.8% for other/unknown-cause death. The spline test supported departure from linearity (P<0.001); the age-by-period interaction was not significant (P = 0.182), whereas an exploratory age-by-subtype interaction was nominally significant (P = 0.024, unadjusted for multiplicity).
Older age was associated with higher mortality, especially in the first year after diagnosis. ALL/LBL-attributable death predominated by registry attribution even in the oldest group. The 3-year comparison did not establish a survival difference between 2015–2019 and 2020-2023; limited follow-up and residual case-mix differences preclude concluding that progress has stopped.
Introduction:
Survival differences by age are well recognized in adult acute lymphoblastic leukemia/lymphoma (ALL/LBL), but their timing, competing-mortality structure, and behavior across recent diagnosis periods remain less clear.
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