Chemo brain — the memory problems and foggy thinking that many cancer patients report after being treated for cancer — isn’t all in the patient’s head. In the past, some doctors have argued that cancer patients experience these often-reported cognitive difficulties because they are depressed, not because of any real physical change in their brain.
However, a new study published Thursday in the Journal of the National Cancer Institute challenges that idea. An University of California Los Angeles team headed by Dr. Patricia Ganz found that chemo brain is a genuine side effect of chemotheraphy.
By carefully testing both breast cancer patients and healthy women, the team was able to show that the women who went through chemotherapy had measurable changes in their ability to think and to remember.
Over 23 percent of breast cancer patients had more trouble remembering than healthy women, and 19 percent had more trouble with reasoning and problem-solving. All told, about 20 percent — one in five — breast cancer patients can expect to have problems with memory or reasoning as a side effect of their cancer treatment.
The UCLA team also demonstrated that patients who received more intensive treatment had a higher risk of chemo brain. Patients who got combined radiation and chemotherapy felt foggier and also suffered more symptoms of depression.
The new study supports a February publication in the European Journal of Neuroscience, which suggested that prolonged chemotherapy decreases the development of new brain cells and interferes with the formation of new memories.
In that report, lead researcher Dr. Tracey Shors and her team found that a chemotherapy drug called temozolomide (TMZ) prevented lab rats from learning new tasks.
While Ganz’s study was performed on breast cancer patients, Shors noted that around 15 percent of all cancer patients — not just breast cancer survivors — report problems with chemo brain.