Invisible wounds: Suicide in military service members with lymphoma

Abstract Background: Although U.S. military service members (SMs) with lymphoma have demonstrated superior survival compared to the general population with lymphoma (Ancira et al., 2022, PMID: 37256781), the long-term impact of military deployment as a psychosocial risk factor, particularly in relation to suicide during survivorship, is poorly understood. Post-9/11 deployments involve unique environmental exposures and psychological stressors. Mental health sequelae including PTSD, depression, and traumatic brain injury are prevalent among U.S. military SMs, particularly post-deployment (Kim et al., 2023, PMID: 37652994). SMs and lymphoma survivors both represent populations that are at elevated risk of experiencing significant psychosocial stress. In civilian populations with hematologic malignancies, suicide risk is significantly elevated within the first 3 years after diagnosis, particularly among those with a history of mental health problems (Hultcrantz et al., 2015, PMID: 25155101). The mental health impacts of deployment thereby provide a rationale whereby deployment might lead to elevated suicide risk following a diagnosis of lymphoma. Methods: Tricare-eligible SMs and retirees diagnosed with Hodgkin lymphoma and non-Hodgkin lymphoma between 2001–2022 were identified from the Department of Defense Cancer Registry using ICD-O codes for lymph node site of origin as well as histology (ICD–O–3 9590 to 9720). Deployment data were obtained from the Defense Manpower Data Center and death certificate data from the National Death Index. Death by suicide was captured by ICD-9 codes E950-E959 and ICD-10 codes X60–X84. The association between history of deployment and death by suicide was estimated by Cox proportional regression estimating the hazard ratio (HR) and 95% confidence interval (95% CI) adjusted for: age at diagnosis with lymphoma (continuous), race/ethnicity, active-duty status, military branch, lymphoma subtype, and stage. Results: A total of 3,644 military personnel with lymphoma were identified, including 830 who were previously deployed and 2,814 who were not previously deployed. Suicide was the cause of death in 8 individuals, including 2 previously deployed (0.2%) and 6 non-deployed (0.2%), adjusted HR=1.53, 95% CI=0.23-10.13. All SMs who died of suicide were men, and 7 out of 8 had non-Hispanic white race/ethnicity. The median time from lymphoma diagnosis to suicide was 8.5 years (range 6.3 to 9.8 years for previously deployed and 4.2 to 15.9 years for non-deployed). Among those who died of suicide, the 2 previously deployed SMs both had nodular sclerosis Hodgkin lymphoma, while lymphomas represented in the 6 non-deployed SMs include diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, small lymphocytic lymphoma, and T-cell lymphoma. Conclusions: Despite elevated mental health burden among post-deployment SMs, crude suicide risk in military lymphoma survivors was low and risk was not found by multivariate analysis to differ appreciably between those with and without prior deployment, although statistical power was limited. Notably, suicides occurred after prolonged latency into survivorship. The small numbers of suicide and long latency after lymphoma diagnosis may reflect good access to mental health services and survivorship care among Tricare-eligible SMs. Disclaimer: The opinions and assertions contained herein are those of the authors and do not reflect those of the Uniformed Services University, Walter Reed National Military Medical Center, or the Department of Defense.