Study of breast cancer patients suggests ‘chemo brain’ is real

Here’s new evidence that the condition known as “chemo brain” is real: A study of breast cancer patients finds that women who had chemotherapy along with surgery to treat their disease had more trouble kicking their brains into high gear than women who were treated with surgery alone. They also performed much worse on tests of mental function than a group of healthy women who served as controls.

The study, published Monday in Archives of Neurology, included 25 breast cancer survivors who had surgery and chemotherapy, 19 breast cancer survivors who had surgery but no chemotherapy, and 18 women with no history of breast cancer who were picked because their ages, level of education and menopausal status were similar to those of the women who had chemo. All of the study volunteers were asked to solve a series of brain teasers while their brain activity was recorded by an MRI machine. Volunteers also took a standardized test to measure their “executive function” and another test to assess how well they thought their brains were working.

The functional MRI results showed that areas of the brain involved in memory, planning and attention weren’t as active in the women who had chemo as in the other breast cancer survivors or the healthy controls. The women in the chemo group took longer to recognize patterns in a card-sorting game administered by a computer. Worse still, “even though the chemotherapy-treated women took more time on this task, they still made more errors,” according to the study.

The results probably won’t come as a surprise to these women – in the tests used to assess how well they thought their own brains were functioning, the women who had chemo reported more problems with executive function tasks than women in the other two groups.

(The researchers also noticed some functional differences in the brains of breast cancer survivors who did not have chemo, but those differences didn’t seem to translate into problems with problem-solving tasks.)

The findings suggest that chemotherapy may cause “neurotoxic brain injury,” the study authors wrote.

But it’s also possible that the disease itself may be responsible. After all, the women who got chemo tended to be diagnosed with more advanced cases of breast cancer than the women who were treated with surgery alone. Teasing apart whether the aggressiveness of the cancer or the chemo used to fight it is most to blame will take further study, the authors wrote.

A summary of the study is available here.

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