UCI Identifies New Therapy for Leukemia : Medicine: Cancer researchers have found that Vitamin A used with a chemotherapy drug can delay the onset of the disease’s acute phase.

Vitamin A used in combination with a chemotherapy drug can prolong the lives of patients suffering from a type of leukemia that most often strikes middle-aged adults, according to a new study by UC Irvine cancer researchers.

In adult patients with chronic myelogenous leukemia, the therapy could delay by as much as eight months the onset of the disease’s acute stage, when patients deteriorate rapidly, according to Dr. Frank L. Meyskens Jr., director of UC Irvine’s Clinical Cancer Center and one of the study’s authors.

In rare cases where chronic myelogenous leukemia affects people age 30 and under, the delay could give patients more time to search for a bone marrow donor, researchers said.

The findings, reported Friday at an international cancer conference in Tucson, mark the first significant advance in treatment of the disease in almost three decades and may give researchers clues to developing better therapies.

“People do pretty well in the chronic phase, but once you have the acute phase, there’s really not much time left for survival,” Meyskens said.

In their study, researchers examined 150 patients with chronic myelogenous leukemia, a form of blood cancer that strikes about 5,000 Americans a year, most of them in their 40s and 50s. The disease produces symptoms such as fatigue, anemia and weight loss, and most patients who have it survive for about fours years after diagnosis.

Researchers gave one group of patients chemotherapy using the drug busulfan but gave another group the same drug accompanied by a daily dose of 50,000 units of Vitamin A, about the amount a person would consume in 12 large carrots.

The group that took both lived an average of eight months longer and had a better chance of survival than the group that was given busulfan alone, researchers found.

“The findings require more study, but in years to come we might be treating (chronic myelogenous leukemia) as a completely chronic disease,” Meyskens said. “And people live with chronic disease all the time.”

Because busulfan sometimes produces skin and lung problems as side effects of treatment, it fell out of favor during the 1980s as the drug of choice in treating chronic myelogenous leukemia and is no longer considered standard therapy.

Meyskens said his future studies will examine the effects of Vitamin A acid, a substance related to Vitamin A, with current therapies such as hydroxyurea, another drug used in chemotherapy, or interferon, a substance produced by cells in response to viral infections that is now used to fight some types of cancer.

“It would really be interesting to see the studies with interferon,” said Dr. Howard A. Liebman of USC’s Norris Comprehensive Cancer Center. “It has a dramatic effect in many patients with this disease.”

Bone marrow transplants have been effective in treating leukemia in younger patients, Liebman said. But because they must get bone marrow from a compatible donor, the wait is often very long and only a minority of patients are able to find one.

Delaying the onset of the acute stage of leukemia for these patients, Liebman said, could buy needed time to find a donor.

Meyskens cautioned that people with leukemia should not take Vitamin A without first consulting their doctors. The dose given the patients in the study is “potentially toxic,” he said.