Common chemotherapy drugs can kill healthy brain cells(ZT)

Wed Nov 29, 4:55 PM ET

WASHINGTON (AFP) - Common drugs used to treat cancer patients may do more harm than good by killing healthy brain cells, a research study shows.


The study, which further indicated that chemotherapy can cause long-term brain damage, gives scientists clues to the causes of "chemo brain", a side effect many cancer patients complain of while under treatment, a summary of the research said.

Mark Noble, a specialist in neural stem cell biology at the University of Rochester, New York, led a research team which tested healthy brain cells with normal clinical doses of chemotherapy drugs carmustine, cisplatin and cytosine arabinoside.

The drugs are often used to treat people suffering certain breast cancers, lung cancer, colon cancer, leukemia, brain tumors and some lymphomas.

The study found that the drugs were more toxic to neural cells than to the cancer cells they targeted. The drugs killed 70-100 percent of brain cells, while only 40-80 percent of the cancer cells were killed.

Tested on animal neural cells, the cells kept dying for six weeks after the treatment was administered, the study found.

The scientists were not surprised that all-important dividing stem cells were killed by the drugs, but noted the danger that "the loss of dividing cells has onerous consequences as these populations are responsible for replenishing the other cell types in the central nervous system."

The study, published Wednesday in the Journal of Biology, gave scientists some insight into the causes of "chemo brain": complaints by some four out of five chemotherapy patients of neurological side effects such as loss of memory, loss of vision, seizures and sometimes dementia.

"This is the first study that puts chemo brain on a sound scientific footing, in terms of neurobiology and cellular biology," Noble said in a statement.

A study released in October by the University of California at Los Angeles medical school showed that chemotherapy can provoke changes in a person's metabolism and blood flow in the brain for at least 10 years after the treatment has ended.