Risk of myeloproliferative neoplasms among U.S. Veterans from Korean, Vietnam, and Persian Gulf War eras

The Promise to Address Comprehensive Toxics (PACT) Act expanded U.S. Veterans' health care and benefits for conditions linked to service-connected exposures (e.g., Burn Pits, Agent Orange). However, myeloproliferative neoplasms (MPN) are not recognized as presumptive conditions for Veterans exposed to these toxic substances. This study evaluated the development of MPN among U.S. Veterans from the Korean, Vietnam, and Persian Gulf War eras. This retrospective cohort study included 65 425 Korean War era Veterans; 211 927 Vietnam War era Veterans; and 214 007 Persian Gulf War era Veterans from January 1, 2006, to January 26, 2023. Veterans with MPN, thrombosis, bleeding, and cardiovascular risk factors were identified through ICD-9 and -10 codes. Veterans from the Persian Gulf War era had the highest risk of developing MPN compared with Veterans from the Korean and Vietnam War eras, hazard ratio (HR) 4.92, 95% confidence interval (CI) 4.20–5.75 and HR 2.49, 95% CI 2.20–2.82, both p < .0001, respectively. Vietnam War era Veterans also had a higher risk of MPN development compared with Korean War era Veterans, HR 1.97, 95% CI 1.77–2.21, p < .0001. Persian Gulf War era Veterans were diagnosed with MPN at an earlier age, had higher risks of thrombosis and bleeding, and had lower survival rates compared with Korean War and Vietnam War era Veterans. This study reinforces evidence that environmental and occupational hazards increase the risk of clonal myeloid disorders and related complications, impacting overall survival with MPN. Limitations include the inability to confirm clonality and fully verify deployment and exposure status.