According to several studies published or forthcoming in the next few days, chemotherapy weaken the brain. As a result of their chemotherapy, approximately 80% of cancer patients say they have cognitive problems, (known in English "Chemobrain") such as memory loss, confusion and difficulty concentrating.
In an article published in Journal of Biology by the team of Mark Noble, a professor at the University of Rochester in New York, 3 anticancer agents, cisplatin (breast cancer), carmustine (brain tumors) and cytarabine (leukaemia and lymphômes), cause toxicity on neural cells in culture and in mice.
In the case of cell cultures, the dosage necessary to degrade 40 to 80% of cancer cells also damage 70 to 100% of neural cells healthy. In mice treated with chemotherapy at doses comparable to those used in humans (in weight ratio concentration), the number of cell division continues to decline despite the discontinuation of treatment for several weeks. The cells are particularly vulnerable neurons in the hippocampus, important in setting the record, and oligodendrocytes, responsible for myelination axons allowing a rapid transmission of information.
In a forthcoming publication in the journal Cancer, researchers of the Japanese National Cancer Hospital East "Chiba have also shown that patients with breast cancer have altered brain regions as a result of chemotherapy. They showed that after stopping chemotherapy, volumes occupied by cognitive areas (prefrontal gyrus, cungulaire and parahippocampe) are significantly reduced. Three years after chemotherapy, these volumes are identical among women treated with chemotherapy and women made for their breast cancer, suggesting powers of recovery previously unknown brain.
In a third study published in the journal Breast Cancer Research and Treatment, the team of Daniel Silverman of the University of California, Los Angeles has shown that women suffering from "chemobrain" had a change of activity and functioning of frontal cortex, even ten years after stopping treatment.
According to Stewart Fleishman, a member of the Beth Israel Medical Center "and" St. Luke's-Roosevelt Medical Center, these phenomena had been seen for a long time, but now there are some neuropathological evidence of adverse effects of chemotherapy on the brain. A drug marketed under the name of Focalin, usually used against hyperactivity, is prescribed to limit the cognitive problems associated with chemotherapy.
For Mark Noble, these results call into question the longstanding theory that chemotherapy drugs target only those cells dividing fast and save quiescent cells and mature. This does not mean it should stop treating cancers with chemotherapy but we must also take into account the dangerous and long-term effects of these drugs. Noble also said work on opportunities to reduce such damage without interfering in cancer therapy.
