Tamoxifen's Mental Side Effects Are Real: Study
But researchers also found drug that may counteract problem from breast cancer treatment
"Every time we can improve quality of life and still treat cancer, it's a win," she said, but noted that it would still be years before this drug might be available.
For the study, Noble and his research team first sought to identify whether brain and central nervous system cells were sensitive to tamoxifen. They found one type of cell that was particularly vulnerable to the drug. After just two days of exposure to tamoxifen at levels similar to those someone in treatment would receive, 75 percent of these cells died.
"Tamoxifen causes cell death and suppression of cell division in these cells," Noble said.
The next step was to try to find a medication that could protect these cells from tamoxifen while still allowing the drug to keep its cancer-fighting ability. The researchers reviewed data on drugs that were already approved for use in humans or that were in clinical trials.
Noble said by looking at these types of drugs, they could save time because they already know that such drugs work in the body and that they're not toxic. They found one drug, currently called AZD6244, that protected the brain cells of mice against tamoxifen in their own study.
Scientists note, however, that research with animals often fails to provide similar results in humans.
"AZD6244 is being studied for cancer therapy. It protects normal cells, but it doesn't protect cancer cells. It may even make cancer cells more sensitive to some types of therapies," Noble said.
Noble said this work needs to be replicated by other researchers, and added that "it's essential that we find ways of treating cancer without causing this type of damage."
Results of the study were published online Sept. 17 in the Journal of Neuroscience.