Agent Orange Exposure, Cytogenetics, and Clinical Outcomes in Multiple Myeloma and MGUS Patients

Background While considerable research has examined transformation from monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) and the association of Agent Orange (AO) with MM, adverse cytogenetics are understudied. Purpose To evaluate associations between AO and adverse cytogenetics or other poor prognostic factors such as abnormal light chain ratio in aged veterans with MM. Materials and methods Vietnam -era Veterans diagnosed with MM or MGUS at a Veterans Health Administration site were identified. Chart review abstracted presence of 17p13, t(4;14), t(14;16), t(14;20), and Gain lq by FISH (dubbed FISH-5) and q13/13q14 deletion, kappa/lambda ratio <.03 / >32 for MM (<.256 / >1.65 for MGUS), and bone marrow plasma cell percentage for MM. Results Among 238 veterans, 70 had MM and 192 MGUS; 24 had both diagnoses (transformation). In MGUS, AO was not associated with transformation, although kappa/lambda ratio was. In MM, Hispanic veterans had more AO exposure. Survival was unassociated with AO or adverse cytogenetics, while Hispanic veterans experienced increased mortality. Conclusion Our study explored cytogenetics in MM among surviving Vietnam Veterans with and without AO exposure. Although Hispanic veterans were more likely to have AO exposure, Hispanic ethnicity but not AO was associated with poorer survival.