Cancer diagnosis: why the brain suffers too

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MunichThe diagnosis of cancer is always a shock. In breast cancer patients, the horror is so deep that it can impair their mental performance.

For a long time it was assumed that only breast cancer patients who endure chemotherapy develop cognitive disorders: some of them become forgetful, have trouble concentrating and their general mental performance declines. "Chemobrain" is what experts call the phenomenon, in English "chemo brain". Many of them speculated that it was the toxic cocktail of drugs that was affecting brain function.

Loss in the organ of thought

But the term chemobrain may not fit as well as expected - the cognitive problems could also have a completely different cause. The first performance losses in the thinking organ appear shortly after the diagnosis - and thus some time before chemotherapy. The diagnosis alone is apparently enough to weaken the brain in its performance.

This could be due to the emotional stress caused by being diagnosed with a life-threatening illness. "Cancer patients can experience their condition as trauma," says Kerstin Hermelink from the Munich University Hospital. In fact, quite a few breast cancer patients developed symptoms of post-traumatic stress disorder. In addition to sleep disorders, this includes recurring, stressful memories in connection with the disease. "And especially shortly after they received the diagnosis," explains the psychologist.

Stress affects thinking

It can already be seen in everyday life that stress affects the performance of the brain: blackouts in exam situations are just one example of this. “Stress has been shown to have a significant influence on cognitive performance. Post-traumatic stress definitely affects brain function, ”says Hermelink. It was therefore suggested that the cognitive losses in breast cancer patients could be the result of the excessive stress that is associated with a cancer diagnosis.

To test this hypothesis, the researcher and her team examined 166 women who had been diagnosed with breast cancer. The control group consisted of 60 women whose breast examination had shown no evidence of a tumor. The participants were examined for their cognitive abilities at three points in time over the course of one year after the diagnosis. Hermelink was initially interested in the test results before the start of therapy.

Reduced attention

These showed that healthy participants and cancer patients performed equally well in almost all tests. In a special attention test, however, the error rate of women diagnosed with breast cancer was significantly higher - even before the cancer was treated. This suggests that later mental losses may not - or at least not only - be based on the side effects of the chemotherapy drugs, but at least also - are consequences of the stress caused by the disease. Hermelink sees this positively. “Our results are good news for cancer patients. "We did not find any indications that patients suffered from anything other than minimal cognitive disorders that are caused by stress before starting treatment."

Source: Hermelink, K. et al. 2015. Elucidating Pretreatment Cognitive Impairment in Breast Cancer Patients: The Impact of Cancer-related Post-traumatic Stress. JNCI. 10.1093 / jnci / djv099

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