19 December 2017
Up to 70% of patients treated for breast cancer experience some degree of cognitive dysfunction (more commonly known as “chemobrain”) during and immediately after treatment, and the symptoms may persist in up to 15-25% of patients. The impact on quality of life and ability to work varies; patients may experience forgetfulness, challenges with multitasking, and difficulty finding words and may even struggle to learn new information. Older patients are more likely to be affected but any patient who has been treated with chemotherapy or even endocrine therapy may note changes in mental function. Multiple factors contribute to the development of cognitive dysfunction, including toxicity of the chemotherapy agents specific to the brain and nervous system as well as other medical conditions, genetic factors and aging. The diagram below is from a recent review in the Journal of Oncology Practice (Lange, Joly) and demonstrates the complex interactions:
Persistent cognitive impairment after treatment can have significant negative effects including reduced adherence to oral medications, diminished self-confidence, and negative impacts on personal and work relationships. It can be challenging, especially in older patients, to sort out which symptoms are related to treatment versus aging and possible neurologic disease.
Unfortunately, while there has been an awareness about treatment related cognitive impairment for some time (especially among patients!) this is a relatively new area for research. An editorial accompanying the Journal of Oncology Practice article (Vardy, Dhillon) notes that as the specific mechanisms by which cognitive dysfunction develop are not known, there are few evidence-based recommendations for prevention or treatment. In addition, studies often show little correlation between a patient’s subjective assessment of their cognitive function and performance on a standardized test designed to be more objective. Factors such as anxiety, depression, and fatigue are associated with (patient) perceived cognitive impairment, but are only weakly associated with objective measures of impairment.
Complicating matters further, the authors note that cognitive rehabilitation programs have been shown to improve subjective cognitive function, but the results are mixed regarding improvement in objective measures.
A second editorial (Baer) provided some practical guidance. The author recommended that physicians work with their patients to review and streamline medication lists, eliminating medications for anxiety, pain and sleep if no longer needed. Basic lifestyle patterns such as sleep habits and diet and exercise routines should be discussed. Patients should be encouraged to start a daily exercise program (with physical therapy referral if needed). Laboratory studies to assess for anemia, vitamin deficiencies and thyroid function should also be performed with corrective action taken if indicated. Coordination with the patient’s primary care physician should take place to ensure that other medical problems such as diabetes, hypertension, and sleep apnea are controlled as much as possible. If depression and/or significant anxiety are present, these need to be addressed and treated. Yoga and other meditative practices have also been suggested.
Additional research is certainly needed. In the meantime, patients should should realize first that the changes they are experiencing are real. Patients should be encouraged to discuss their symptoms and possible solutions with their treatment team.
The articles referenced above are behind a “paywall”. If anyone is interested in the full text article please feel free to email me: contact at drattai dot com and I will be happy to provide them.