“Chemobrain” improves following the end of treatment

This study measured the long-term effects of chemotherapy on cognitive function in breast cancer patients.

As increasing numbers of breast cancer patients are surviving for years following treatment, it is becoming more important to understand the long-term effects of these treatments. Cognitive (mental processing) difficulties, also known as “chemobrain”, are experienced by many patients during treatment: one study reported as many as 61% experienced cognitive dysfunction. While it is not clear what causes chemobrain; possibilities include cell damage due to the toxicity of the chemotherapy agents, inflammation or injury to nerves, or hormonal changes.

While some short-term studies have noted improvements in cognitive function following the end of treatment, the long-term effects are still unclear. The current study followed breast cancer patients for up to three years following diagnosis to measure cognitive function.

This study included 1557 breast cancer patients who completed a series of cognitive tests at 18 months and 36 months (3 years) following diagnosis. Cognitive function was measured by testing the immediate and delayed memory, language fluency, and attention.

When comparing test results at 3 years to those at 18 months, 56.58% of patients improved on immediate memory and 58.08% improved on delayed memory. 49.77% improved on a test of language fluency, and 56.12% improved on a test of attention. Improvements were seen regardless of the treatment used, but no improvements were seen in patients who did not undergo treatment.

This study concluded that though breast cancer treatments such as chemotherapy can cause cognitive difficulties, these impairments improve following the end of treatment.

This study does not compare cognitive function prior to diagnosis to that of 3 years following diagnosis, therefore it is unclear whether cognitive function returns to its normal level.