UC Irvine to Test Vitamins’ Power to Prevent Cancer

UC Irvine researchers have received a $4.2-million grant from the National Cancer Institute to investigate whether large daily doses of two vitamins will prevent cancer in heavy cigarette smokers.

The five-year study, one of the largest of its kind, will involve 4,300 Orange County volunteers who are being recruited from the ranks of healthy men and women, ages 50 to 69, who smoke regularly or used to smoke.

The study, using the vitamins beta carotene and a Vitamin A derivative called retinol, could be very important for America’s smokers, said UCI cancer center director Dr. Frank Meyskens, the study’s principal investigator.

“If it shows this (regimen) makes a difference, all people who are smoking or have smoked will be advised to take beta carotene and retinol,” Meyskens said.

Previous studies have suggested that these vitamins may help prevent cancer. Also, a 1983 French study involving less than 100 volunteers indicated that large doses of another Vitamin A derivative could reverse smokers’ precancerous lesions. But “to date this has not been scientifically proven,” Meyskens cautioned.

For now, there are no reliable ways to treat lung cancer, other than surgical removal of a tumor, noted UCI pulmonary specialist Dr. James H. Williams, a co-researcher with Meyskens. “There are therapies which suppress the tumor and prolong the survival rate but do not cure the cancer,” Williams said. “Preventing it would certainly be a wise idea.”

The grant is one of the largest ever won by UCI researchers. (The university’s largest grant last year was $2.63 million for computer science.)

UCI’s study group, which at its peak is expected to require a 19-member staff, is the latest entry in a $50-million national project aimed at arresting lung cancer in smokers and asbestos workers.

Started in 1983 by researchers at the Fred Hutchinson Cancer Center in Seattle, the project--dubbed the Caret Trial for its use of beta carotene--is directed by oncologists at the Fred Hutchinson Cancer Center in Seattle.

When they are finished, probably in 1998, scientists hope to have tested the vitamin regimen on 17,000 volunteers--13,000 smokers and 4,000 asbestos workers--in Baltimore, New Haven, Portland, San Francisco, Seattle and now Irvine.

“This is the largest study of its kind in cancer prevention” that involves the general public, said Dr. Gary Goodman, an associate professor of medicine at the Hutchinson center and one of the project’s two principal investigators. The only comparable study, he said, was one by the Harvard Medical group that tested the impact of beta carotene doses and aspirin on 40,000 physicians.

Seven thousand volunteers are taking part in this double-blind study--each asked to take a single capsule a day containing either a placebo or a 30-milligram dose of beta carotene, plus 25,000 international units of retinol, the Vitamin A derivative that is found in liver and other meats. That’s about five times the minimum daily requirement for Vitamin A, Goodman said. The beta carotene is found in yellow and green leafy vegetables and carrots and this dose, Goodman said, “is like eating 10 to 20 carrots a day.

So far, no volunteer has reported toxic effects, Goodman said, although some have developed minor side affects--a slight, yellowish cast to their skin from the beta carotene, dry skin and occasional headaches.

Goodman is hoping the vitamin regimen could lead to a 30% decrease in lung cancer but cautions that he will not have reliable data until all 17,000 volunteers have been tested. For now, two of every 1,000 people over age 50 who smoke a pack of cigarettes each day are expected to develop lung cancer, he said.

In Orange County, the Caret Trial will be seeking volunteers through mass mailings to local Blue Cross and Kaiser-Permanente members. Letters to Blue Cross members are to go out this week. Members of the general public may participate by calling (714) 634-7166.

Those who join must fill out a medical history questionnaire, provide a blood sample and report for an initial interview, then return once a year for the next five to eight years for follow-up interviews.

Surprisingly, only 10% of the study’s volunteers have dropped out, researchers said. “It’s a very special group of dedicated people taking part in this study,” Goodman said. And though in the end it may cost $50 million, Goodman said it is a relatively small price to pay. “When you consider that 140,000 people die every year from lung cancer, in lives lost, care for them--that’s many billions of dollars a year. If this works, it would be an enormous savings.”