Agent Orange is made up of compounds known to be contaminated with the dioxin tetrachlorodibenzo-para-dioxin (TCDD) during manufacture. The chemical was named for the color of the barrel it was stored in and was one of the "broad-leaf defoliants" used in Vietnam to destroy vegetation to make enemy activity easier to see.
Between 1962 and 1971, more than 20 million gallons of Agent Orange were sprayed during the war, contaminating both the ground and soldiers. The International Agency for Research on Cancer reclassified TCDD a group 1 carcinogen in 1997, a classification that also includes arsenic, asbestos and gamma radiation, according to background information with the study.
Dr. Bruce Roth, a professor of medicine and urologic surgery at Vanderbilt University, said he found the study interesting but not persuasive.
"I'm not totally convinced," Roth said, noting that the study relies on self-reported exposure to Agent Orange, without other objective proof of exposure or the amount of exposure.
Roth speculated that because all study participants who reported being exposed to Agent Orange were given thorough screening tests for prostate cancer, more cancers were found. "I can almost guarantee you're going to find more cases of prostate cancer," he said.
"I'm not saying that there is not possibly some relationship, but I don't think that this paper necessarily proves it," Roth said. "But I think you could pick almost any exposure and increase screening, and you are going to find more cases, whether or not the agent is responsible for more cases or not."
Dr. Michael J. Thun, vice president of epidemiology and surveillance research at the American Cancer Society, agreed that the findings were interesting but don't prove a connection between prostate cancer and Agent Orange.
"The finding is provocative, but it's hard to know how to interpret it, unless it can
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