Cancerous stem cells researched

NEW YORK, Dec. 21 (UPI) -- Researchers at three U.S. medical centers are testing a cancer drug under the theory that some cancers are fed by cancerous stem cells.

The researchers said cancerous stem cells are aberrant cells that maintain and propagate malignant tumors. The stem cells may be impervious to most standard cancer therapies, The New York Times said Friday.

While critics say the stem cell enthusiasts are heading down a blind alley, proponents of the theory are looking for ways to kill the stem cells, the newspaper said.

Proponents of the hypothesis say chemotherapy and radiation often destroy most of a tumor but if they do not kill the stem cells, it can grow back.

The University of Michigan Comprehensive Cancer Center, Baylor College of Medicine in Houston and the Dana-Farber Cancer Institute in Boston plan to begin testing a drug developed by Merck to treat Alzheimer's disease. It did not work on Alzheimer's but kills breast cancer stem cells in laboratory studies, the report said.

The study will start with a safety test on 30 women who have advanced breast cancer.