b'Did Past Military Toxic ExposuresIncrease Risk of AML, MDS in Veterans?A half-century after Agent Orange use ended, the debate continues over whether exposure to the herbicide in Vietnam and elsewhere contributed to the development of acute myeloid leukemia and myelodysplastic syndromes. A recent article from Yale researchers raised the issue anew. By Brenda L. MooneyNEWHAVEN,CTTheVietnamWarendedThe acknowledgement that the known carcinogen 47 years ago, and the use of the herbicide AgentTCDD was a contaminant in AO when paired with Orange was banned by the United States 51 yearsa strong biological plausibility for its leukemogenic-ago, but debate continues over whether acute my- ity and an observed increased risk of AML/MDS in eloid leukemia (AML) and its often-related condi- TCDD-exposed individuals should suffice to estab-tion,myelodysplasticsyndromes(MDS)shouldlish causal association and that veterans to whom becomepresumptiveconditionsrelatedto Agentthismightapplyshouldbeawardedappropriate Orange exposure. indemnity, they concluded.As has been the case for decades, research resultsThe VAs presumptive list already includes chronic have been mixed on the question of whether AMLB-cell leukemias, added in 2003, as well as the blood and MDS in veterans is caused by toxic exposurescancermultiplemyeloma,addedin2016.Sofar, during military service. however, AML and MDS have not been added to The issue was raised anew when, earlier this year,the list. (AML is technically not a B-cell lymphoma, twoprominentspecialistsfromYaleUniversityalthoughpaststudieshavesuggestedthatAML School of Medicine and Yale Cancer Center wrotepatients have elevated rates of a type of B cells, Breg inthejournalLeukemia&Lymphoma,Agentcells, and that might reveal poor prognosis.Orange (AO) was the dominant weaponized herbi- It is notable that numerous hematologic malignan-cide employed by the United States (US) militarycieschronic B cell leukemias, multiple myeloma, during the Vietnam war. AO, however, was foundlight-chain amyloidosis, Hodgkin disease, and non-toberegularlycontaminatedby2,3,7,8-tetrachlo- Hodgkin lymphomaand some other cancers are on rodibenzo-p-dioxin (TCDD), the most toxic dioxinthe presumptive list, but not MDS or acute myeloid known; furthermore, AO was commonly diluted inleukemia, David Steensma, MD, of the Dana-Farber the field with other aromatic hydrocarbons to assistCancerInstituteinBostonwroteontheAplastic with delivery mechanisms. Anemia & MDS International Foundation website.The authors, Rory M. Shallis, MD, and Steven D.The American Cancer Society reports that about Gore, MD, went on to state, Unbeknownst to the20,050 new cases of AML occur each year, mostly in U.S. military and the millions exposed, these eventsadults. Nearly all of the 11,540 deaths are in adults, have likely contributed to the development of acuteit adds.myeloid leukemia (AML) and myelodysplastic syn- While AML is one of the most common types of drome (MDS) that has affected many veterans. leukemia in adultsand the most common type of Shallis and Gore argued that studies failing to findacute leukemiait still accounts for only about 1% an association between AO exposure and AML/MDSof all cancer cases. The deadly cancer also is a dis-arelimitedintheirmethodologyandapplication.ease of older people and is uncommon before the age 54'