Age-related early mortality and competing-risk outcomes in angioimmunoblastic T-cell lymphoma: a SEER-based population study

BACKGROUND: Angioimmunoblastic T-cell lymphoma (AITL) predominantly affects older adults, but the distribution of deaths soon after diagnosis between lymphoma and competing causes is uncertain, particularly in octogenarian patients. METHODS: We analyzed patients with AITL in the SEER 17 Registries database. The stage-adjusted main cohort included diagnoses from 2000 to 2015; a stage-unadjusted sensitivity cohort extended through 2021. Patients aged <60 years served as the reference group. Fixed-window logistic regression, Kaplan-Meier and Cox analyses, cumulative incidence functions, Fine-Gray models, and cause-specific Cox models were used. Deaths with unknown cause were retained as a third competing event. RESULTS: Among 1,516 patients, recorded chemotherapy use decreased from 83.7% at age <60 years to 52.2% at age ≥80 years, while 6-month mortality increased from 13.5% to 41.6%. In octogenarian patients, 91 AITL-specific deaths (35.7% of the age group), 15 non-AITL deaths (5.9%), and no unknown-cause deaths occurred within 6 months; AITL-specific deaths comprised 85.8% of recorded 6-month deaths. Relative to age <60 years, age ≥80 years was associated with 6-month all-cause mortality (OR 3.890, 95% CI 2.628-5.756), AITL-specific death (sHR 2.034, 95% CI 1.645-2.516), and non-AITL death (sHR 3.663, 95% CI 2.399-5.594). Stage-unadjusted analyses through 2021 showed similar age gradients. CONCLUSIONS: Early mortality increased sharply with age in AITL. Most recorded early deaths among octogenarian patients were classified as AITL-specific, while competing non-AITL mortality also increased. These findings support prompt lymphoma assessment, geriatric evaluation, and treatment planning that jointly considers disease control and competing risks.