Beta Carotene Focus of UCI Cancer Study : Medicine: Researchers in Orange will be among the latest to look at this nontoxic substance and its role in preventing cancer.

ORANGE —  Two researchers at UCI Medical Center have received a $170,000 federal grant to study whether large doses of a natural substance called beta carotene can reduce oral lesions and so prevent head and neck cancer.

Their three-year study, funded by the National Institutes of Health, is among the latest to look at the nontoxic substance and its role in preventing cancer.

Beta carotene is found in leafy green and yellow vegetables, including carrots and broccoli, and converted to Vitamin A, or absorbed as Vitamin A, in the digestive tract.

Scientists have been studying beta carotene’s potential for preventing cancer since the early 1980s, said Florence S. Antoine, a spokeswoman for the National Cancer Institute in Bethesda, Md. The institute has funded research into whether it can prevent a variety of cancers including lung and skin cancer.

“We don’t know that it is effective, I don’t think, for certain,” Antoine cautioned. “It’s not at that point yet. It’s all being looked at.”

But Dr. Frank Meyskens, director of UCI’s Clinical Cancer Center, an expert in cancer prevention and one of the UCI’s researchers in this project, said the evidence so far is promising.

In a smaller study at the University of Arizona, beta carotene eradicated oral lesions in 15% of the 25 volunteers who took it for six months and produced a partial remission in 35% of them, said Meyskens, who was involved in that 1989 study.

In the upcoming UCI study, researchers are seeking 150 adults ages 18 to 80 who have leukoplakia --a white discoloration of the mouth or throat that gradually progresses to cancer.

Those participants will take beta carotene in the form of a pill that is the dietary equivalent of six large carrots a day, “but is easier to take,” Meyskens said.

If the UCI study shows that beta carotene can eradicate the lesions, it could then be given as a preventive measure to people who are considered high-risk for head and neck cancer, he said.

Some 43,000 Americans a year develop those cancers, said Meyskens’ co-researcher, Dr. James Pitcock, director of head and neck surgical oncology at UCI. “The precancerous leukoplakia are most common in users of cigarettes, snuff and alcohol and those are the people we see most often developing oral cancer,” Pitcock said.

Unlike painful chemotherapy regimens that cause debilitating side effects in cancer patients, beta carotene may be able to prevent precancerous conditions with no toxic side effects, Meyskens said. The only effect of large doses of beta carotene is that users may develop a slight yellowish tinge to the skin.

“It’s very exciting to think that a fairly benign substance can reverse a precancerous condition,” Meyskens said.

Those with leukoplakia who are interested in participating in the UCI study should call the cancer center information line at (714) 634-6316. Meyskens noted that those who have had oral cancer and women of childbearing age are not eligible to participate.