(Feature Impact) A new study found U.S. veterans exposed to Agent Orange face a higher risk of developing a rare and often overlooked form of melanoma that appears on the hands and feet, and under the nails.

Researchers reported in “JAMA Dermatology” that veterans with documented exposure to the herbicide had significantly higher odds of developing acral melanoma, a subtype of skin cancer that forms on the palms, soles and nail beds.

Unlike most melanomas, which are associated with ultraviolet radiation, acral melanoma develops in areas not typically exposed to the sun. It can resemble a bruise under a toenail or a dark patch on the bottom of a foot – locations that are easily missed and not commonly associated with skin cancer.

Because of its unusual appearance and location, acral melanoma is often diagnosed at later stages, when treatment is more difficult and survival rates are lower.

The researchers analyzed 20 years of Veterans Health Administration data, comparing more than 1,200 veterans diagnosed with acral melanoma with more than 5,000 veterans without melanoma. Veterans exposed to Agent Orange had about 30% higher odds of developing the disease.

The findings suggest Agent Orange may be an underrecognized risk factor for acral melanoma, particularly for veterans who may not view themselves as at risk for skin cancer because of limited sun exposure or darker skin tones.

“Identifying exposures that may increase risk can help inform earlier recognition and, ultimately, earlier diagnosis when treatment is most effective,” said Marc Hurlbert, chief executive officer of the Melanoma Research Alliance and a principal investigator on the study.

Senior author Dr. Rebecca I. Hartman of Brigham and Women’s Hospital said acral melanoma behaves differently from other melanomas and often responds less well to current therapies.

“Acral melanoma has a poorer prognosis than the more common cutaneous melanoma because it is often diagnosed at later stages,” Hartman said. “Identifying risk factors is critical to improving detection and outcomes.”

Agent Orange was used extensively during the Vietnam War and exposure has been linked to several cancers and chronic illnesses. These findings add to evidence the herbicide may also affect the skin in ways not reflected in traditional melanoma awareness efforts.

Acral melanoma has also been associated with sex, race and ethnicity, and prior skin lesions. Researchers said the study supports treating the disease as distinct from sun-driven melanomas that dominate public education campaigns.

For veterans, the research highlights the importance of examining less visible areas of the body, including the bottoms of the feet, between the toes and under the nails. Changes in nail color, dark streaks or unexplained spots on the palms or soles should be evaluated by a health care provider, especially for those with known Agent Orange exposure.

Researchers said the findings could help guide future screening strategies for higher-risk populations and encourage further study of why acral melanoma differs biologically from other skin cancers.

Find more information at curemelanoma.org.

Photo courtesy of Shutterstock

Source: Melanoma Research Alliance