The Vietnam War ended in 1975, but - even 4 decades later - high rates of non-melanoma invasive skin cancer are reported in Vietnam veterans exposed to the controversial herbicide Agent Orange, according to a new study published in the journal Plastic and Reconstructive Surgery.
A potent jungle defoliant, millions of gallons of Agent Orange were sprayed across Vietnam in order to remove the forest cover concealing enemy troops and to destroy crops.
Containing a highly toxic dioxic contaminant called TCDD, Agent Orange is linked to a wide range of diseases in humans, including many cancers.
No one knows exactly how many people were exposed to TCDD during the Vietnam War, but about 1.5 million Americans served in Vietnam during the most intense period of herbicide use.
TCDD exposure and cancer risk
During the 1970s, veterans returning from Vietnam began to report rashes, cancer, psychological problems and birth defects in their children. Exposure to Agent Orange was suspected as the main contributing factor.
Although there is now a lot of evidence linking Agent Orange exposure to serious diseases, there are still many questions regarding its adverse health effects that have not been answered.
The link between Agent Orange exposure and skin cancer was first investigated in the 1980s. However, the Veterans Affairs organization, who provide benefits to veterans for health problems caused by TCDD, do not currently recognize skin cancer as being a condition related to Agent Orange.
Veterans twice as likely to develop skin cancer
The researchers behind the new study analyzed the medical records of 100 consecutive Vietnam veterans who enrolled in the Agent Orange registry at the Veterans Affairs hospital in Washington, DC, between 2009 and 2010.
About 1.5 million Americans served in Vietnam during the most intense period of herbicide use.
Of this sample, 56% lived or worked in areas contaminated by Agent Orange, 30% were engaged in spraying Agent Orange and 14% were exposed to TCDD by traveling through contaminated areas.
Overall, 51% of the veterans in the study had non-melanoma invasive skin cancer (NMISC). This is a statistically significant figure - about twice as high as the average rate in men of a similar age. In the veterans who had actively sprayed Agent Orange, the risk of NMISC increased to 73%.
Another skin condition, chloracne, was observed in 43% of the veterans. The rate of NMISC among the veterans with chloracne was 80%. Veterans with lighter skin or eye color also had a higher risk of developing skin cancer.
More studies are needed
The researchers acknowledge there were some problems with their study. They were not able to include a control group - a comparison sample of Vietnam veterans not exposed to Agent Orange - in the study because of the sensitivity around accessing veterans' health records.
Also, as this study required the veterans to recall events from decades earlier, the researchers could not be certain that the information on how long the veterans were exposed to TCDD was accurate.
But the results do strengthen the previous findings between TCDD exposure and risk of NMISC, say the researchers. Dr. Clemens and co-authors say:
"Further studies are warranted to determine the relative risk within this patient population and to determine appropriate management strategies so that veterans may receive the care they earned in service."