By Rob Dillard
US veterans who were exposed to Agent Orange (AO) have an increased risk of myeloproliferative neoplasms (MPNs), bleeding, arterial thrombosis (AT), and venous thrombosis (VT), according to an analysis that will be presented at the 2023 American Society of Clinical Oncology Annual Meeting.
AO is a chemical herbicide that was weaponized and heavily used during the Vietnam War. The chemical is associated with the development of sarcomas and B-cell lymphomas, but, until now, less has been known about its link to MPNs, bleeding, AT, and VT.
To conduct their analysis, lead author Andrew Chua Tiu and colleagues used the VA Informatics and Computing Infrastructure database to identify 95,768 patients with MPN and any AT, VT, and bleeding events.
According to the results, there was a notable correlation between AO exposure and the development of MPNs (odds ratio, 1.61; 95% CI, 1.57-1.65; P<.0001). Specifically, the researchers observed that compared with patients with MPNs who were not exposed to AO, patients with MPNs who were exposed to AO had higher rates of AT (36.0% vs 28.2.%), higher rates of AT (28.7% vs 24.0%), and more bleeding events (41.2% vs 39.0%).
“This is the largest database evaluating MPNs, thrombosis, and bleeding in veterans exposed to AO. There is an association of increased risk of development of MPNs, increased AT, and increased bleeding with AO exposure,” the researchers concluded. They added that further studies “including JAK2 mutation, [clonal hematopoiesis of indeterminate potential], and cardiovascular risk factors will be needed to evaluate contribution to thrombosis and bleeding risk.”
Source: Tiu AC, McKinnell Z, Liu S, et al. Association of Agent Orange and myeloproliferative neoplasms, thrombosis, and bleeding among veterans. Abstract #7011. Published for the 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, Illinois.