Agent Orange Exposure a Risk Factor for Lethal Prostate Cancer: Study

U.S. veterans who have been exposed to Agent Orange are at a high risk of developing a deadly type of prostate cancer, according to a new study. Researchers say that the findings show why veterans exposed to the chemical must be screened for the cancer.

Prostate cancer occurs in tissues of the prostate - a gland that is present below the bladder and in front of the rectum in men.

Previous research had shown that men exposed to the herbicide Agent Orange were at higher risk of developing prostate cancer. However, it wasn't clear if these cancers were lethal. The herbicide, widely used during the Vietnam War, was contaminated with a cancer-causing agent called dioxin.

"This is a very, very strong predictor of lethal cancer," Dr. Mark Garzotto, from Portland Veterans Affairs Medical Center in Oregon, told Reuters Health. "If you're a person who's otherwise healthy and you've been exposed to Agent Orange, that has important implications for whether you should be screened or not screened." Garzotto is the principal investigator of the study.

The U.S. military sprayed millions of gallons of Agent Orange in Vietnam during the war. Exposure to the chemical has resulted in about 150,000 children having birth defects, according to estimates by The Vietnamese Red Cross. The effect of the war has been so severe that women even today get multiple ultrasounds done to ensure the baby has no birth defects. Recently, the U.S. began efforts to cleanup Agent Orange in Vietnam.

The present study included 2,720 U.S. veterans who were referred for a prostate biopsy. Researchers found that at least 32 percent of them, about 896 veterans, had prostate cancer, with 459 having a lethal form of the cancer.

"This is an important distinction as the majority of prostate cancer cases are non-lethal and thus do not necessarily require detection or therapy. Having a means of specifically detecting life-threatening cancer would improve the effectiveness of screening and treatment of prostate cancer," said Garzotto in a news release.

The study is published in the journal CANCER.