Arsenic Fights Rare Form of Leukemia
Patients Could Avoid Standard Chemotherapy, Bone Marrow Transplants
Sept. 29, 2004 -- Arsenic, despite its poisonous nature, may help save lives. Mounting evidence suggests that an arsenic treatment is effective for a rare form of leukemia.
At the European Organization for Research and Treatment of Cancer annual meeting -- held this week in Switzerland -- a group of Iranian researchers discussed new clinical trial findings of arsenic trioxide (its chemical name).
Only about 10% of leukemia patients have the rare condition called acute promyelocytic leukemia (APL). The cancer involves rapid accumulation of abnormal white blood cells in the bone marrow and the blood, resulting in anemia, bleeding, and susceptibility to infection. With standard chemotherapy treatments -- plus a vitamin A-based treatment -- between 60% and 80% of patients live longer than five years.
Arsenic trioxide is already FDA approved for APL. Patients who have had a relapse after their first chemotherapy treatment can get the arsenic treatment.
In fact, arsenic compounds have been used in medicine for thousands of years -- even by the ancient Chinese and Romans. In the 1980s, Chinese researchers first tried it for treating leukemia after finding that arsenic was the active ingredient in some traditional Chinese medicines.
However, the Iranian study showed such "impressive" results that researchers say arsenic trioxide should be considered a first treatment for this rare form of leukemia.
In that study, 63 patients with APL were given arsenic chemotherapy as their first treatment. More than 90% went into complete remission -- they had no recurrences of the cancer. Eighty-nine percent were still alive a year later, with the average survival time being almost three years. Of 11 patients whose cancer returned, eight went back into remission after more treatment with arsenic trioxide. Only six patients died.
The drug appears to work by causing cancer cells to self-destruct. It also appears to correct the gene responsible for making a flawed protein that causes APL.
The patients had better results than standard chemotherapy, says lead researcher Ardeshir Ghavamzadeh, MD, professor of medicine at Tehran University, in a news release.
With this option, APL patients could avoid conventional chemotherapy and bone marrow transplants, Ghavamzadeh says.
SOURCES: News release, European Organization for Research and Treatment of Cancer.