US Veterans, including former Air Force personnel who participated in Operation Ranch Hand, have a 2.4-fold increased risk of multiple myelomaâ€™s precursor state, MGUS,
JAMAthat supports an association between Agent Orange exposure and multiple myeloma.
The goal of the study was to examine the relationship between MGUS and exposure to Agent Orange, including its contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in veterans from the Vietnam War.
Previous occupational studies have shown that other pesticides, such as insecticides and herbicides, are linked with excess risk of multiple myeloma and MGUS, according to Landgren et al, but there are no known studies that have uncovered an association with veterans from the Vietnam War.
This prospective cohort, conducted from 2013 to 2014, tested for MGUS in the serum specimens of veterans that were previously collected and stored by the Air Force Health Study (AFHS).
The AFHS included veterans from Operation Ranch Hand who were exposed to Agent Orange and TCDD, as well as those who participated in similar duties within Southeast Asia but did not come in contact with any herbicides (comparison veterans).
The cohort study chose to include 479 of the exposed US Air Force Vietnam War veterans in the first group and 479 comparison veterans in the second.
Findings from this study reported a crude prevalence of overall MGUS of 7.1% (34 of 479) in the first group and 3.1% (15 of 479) in the second, following an adjustment of age, race, and BMI in 2002, as well as difference in BMI between 2002 and the time of blood draw for TCDD measurement (adjusted OR, 2.37; 95% CI, 1.27-4.44;P= .007).
Ultimately, it was discovered that the veterans exposed during the herbicide spray missions (ie, Operation Ranch Hand) have a significantly increased risk of MGUS, which supports the theory regarding the association between Agent Orange exposure and multiple myeloma.
Landgren O, MD, PhD, Shim YK, PhD, Michalek J, PhD, et al. Agent Orange exposure and monoclonal gammopathy of undetermined significance: an Operation Ranch Hand veteran cohort study.JAMA Oncol. doi:10.1001/jamaoncol.2015.2938.