Beyond the Battlefield: Lymphoma Outcomes in Post-9/11 Service Members and Veterans

Background: Non-Hodgkin lymphoma (NHL) is the most common hematologic malignancy among U.S. military service members (SMs), yet the impact of deployment and deployment-related factors on survival remains unclear. Modern military service involves potential exposure to environmental hazards and trauma that could plausibly influence lymphoma biology, treatment tolerance, or long-term outcomes. Methods: Tricare beneficiaries with NHL diagnosed between 2001 and 2022 were identified from the Defense Health Agency Cancer Registry. Deployment history, demographics, lymphoma subtype, and mortality data were obtained from linked Department of War and National Death Index sources. Survival was compared between previously deployed (9/11 DEP) and non-deployed (NON-9/11 DEP) SMs using multivariable Cox models. Among deployed SMs, associations between deployment characteristics and mortality were evaluated. Results: Among 745 SMs, 378 had deployed, and 367 had not. There were no significant differences in all-cause, lymphoma-specific, or non-lymphoma mortality between cohorts. Deployment location, duration, number of deployments, and occupational category did not affect survival. Histologic differences between cohorts, higher diffuse large B-cell lymphoma and follicular lymphoma in deployed SMs, and higher T-cell lymphomas and marginal zone lymphoma in non-deployed SMs, were more consistent with unmeasured confounding and differential deployability than with deployment-related risk. Conclusions: These findings do not suggest major survival differences attributable to deployment status. Given the lack of publicly available validated exposure assessment tools for military personnel, as current military operations expand, including recent deployments to the Middle East, proactive and systematic approaches to exposure assessment are urgently needed. Strengthening military cancer registries and embedding validated exposure tools will be essential to proactively anticipate, identify, and manage exposure-related hematologic concerns in future Veterans.