A military helicopter in July 1969 sprays Agent Orange over the Mekong Delta, near Can Tho, Vietnam. The image is part of the Bryan Grigsby Collection at the Vietnam Center and Sam Johnson Vietnam Archive at Texas Tech University. (Department of the Army Special Photographic Office)
WASHINGTON — A new study links Agent Orange to more aggressive bone marrow cancers in Vietnam veterans, which researchers say strengthens the case for granting presumptive service-connected benefits to veterans diagnosed with the disease decades after military service.
Known as myelodysplastic syndromes, or MDS, this group of bone marrow cancers disrupts blood cell production, resulting in a low blood cell count, according to researchers at the Sylvester Comprehensive Cancer Center at the University of Miami in Coral Gables, Fla.
The findings shed light on why some Vietnam veterans exposed to Agent Orange have developed more severe bone marrow cancers, said Mikkael A. Sekeres, a physician and chief of hematology at Sylvester Comprehensive Cancer Center.
The study identified genetic mutations tied to earlier diagnosis and faster progression of the disease, he said.
“What we’re seeing is that Agent Orange added a mutation — and that mutation sets patients on the road to cancer 50 years later,” Sekeres said.
The Department of Veterans Affairs recognizes several cancers as presumptively linked to Agent Orange, enabling qualifying veterans to receive disability compensation without proving a direct connection, according to the VA.
Qualifying cancers include but are not limited to certain lymphomas, bladder cancer, multiple myeloma and prostate cancer, according to the VA.
But MDS is not designated as a presumptive condition, which means that veterans must provide the necessary medical evidence to show a direct service connection between herbicide exposure and their disease, according to the VA Disability Group.
“I’m one of maybe several hundred to be compensated for MDS. But there are thousands of us with it who served in Vietnam,” said Bob Macfarlane, an 81-year-old Vietnam veteran on active duty in the Air Force from 1962 to 1968.
“My VA doctors gave me 29 months to live, but only God knows my expiration date,” said Macfarlane, who was diagnosed with MDS in 2005 and obtained a service-connected disability rating five years later.
Macfarlane, a former master sergeant, said spraying Agent Orange was common to clear the dense jungles in Vietnam, and no one questioned it.
Macfarlane said he was able to obtain VA disability benefits for exposure, after challenging repeated denials before the Court of Appeals for Veterans Claims in Washington, D.C.
“There is hope if you don’t give up,” Macfarlane said.
Approximately 2.6 million Vietnam-era service members were potentially exposed to Agent Orange, which contains a highly toxic form of dioxin, a chemical that disrupts cellular processes, according to the study.
The study’s findings shed light on why some toxic-exposed Vietnam veterans have developed more severe bone marrow cancers, said Mikkael A. Sekeres, physician and chief of hematology at Sylvester Comprehensive Cancer Center at the University of Miami in Coral Gables, Fla. (University of Miami)
MDS develops slowly and typically occurs later in life. Most people receive a diagnosis in their 70s. “That long arc between exposure and diagnosis makes environmental risk factors particularly difficult to study,” Sekeres said.
“We have aging veterans developing MDS who are being told by the [VA] that they can’t get their health care covered to the extent they need because there hasn’t been an official association made,” Sekeres said. “This new analysis changes that dynamic. While it does not prove cause and effect, it provides the strongest data to date linking Agent Orange exposure with distinct genetic changes and more aggressive disease.”
Veterans can file for disability benefits for MDS, but they must submit additional medical evidence to support their claim, according to the VA Disability Group.
“This doesn’t mean you can’t collect VA disability benefits from MDS, though the VA has so far refused to add MDS to the Agent Orange presumptive disease list,” according to the VA Disability Group, which assists veterans in filing claims for disability benefits and health care coverage for service-connected medical conditions.
Because MDS commonly occurs in older patients, it is often attributed to age rather than toxic exposure, according to the Mayo Clinic.
Among patients diagnosed with MDS, those exposed to Agent Orange were more than twice as likely to show “high-risk chromosome abnormalities,” Sekeres said.
“For veterans living with MDS, knowing their cancer may have a unique genetic profile offers more than scientific insight. It can influence follow-up care and treatment decisions,” he said.
