Chemo Brain - A Real Issue

Integrative Oncology - Holistic Cancer Care
Dr Bier is a Fellow of the American Board
of Naturopathic Oncology (FABNO), which
helps patients differentiate between
general-practice naturopaths and those
with a specialized knowledge of oncology
Cancer Care - An Interview With Dr. Bier
We sat down with Dr Bier to ask him
about his interest in Oncology care,
and what he does to work with cancer patients

Chemo Brain- A Real Issue

Deciding to do chemotherapy is a complex, multi-variant decision that needs to take into account the potential of both benefit and harm. A foundational concept of informed consent is knowing and balancing the benefits and risk of any intervention.

One of the known harms of chemotherapy is potentially permanent cognitive impairment. Very few to none of our community of cancer patients are informed of the potential cognitive impairment from chemotherapy, and therefore don't include the risk in their thinking. This damage is caused by inflammation in the brain from the chemotherapy, and is seen in endocrine therapies as well (aromatase inhibitors), not just traditional chemotherapy.

Unfortunately, it is an issue that is newer to the literature, and therefore often not yet officially acknowledged although clearly now known. People are much more likely to assume that they'll push through the short-term side effects, however bad they may be, for the chance of the long term benefit. My experience is that once people realize that 'chemo brain' isn't just a cute way of saying you're a little forgetful during chemo; that it's a real, long-term and possibly permanent repercussion, it better informs their decision.

If you have the background and interest, a good 240 page read trying to summarize the known science is Chemo Fog: Cancer chemotherapy-related cognitive impairment. 

For the rest of us, a good general article is  Understanding ‘Chemobrain’ A Challenge and Invitation for Psychological Scientists. Although slightly technical, it's written for psychologists, not neuroscientists, so is very understandable and does a good job at highlighting the pertinent issues. An illustrative quote from that article:

"Between 20% and 61% of breast cancer patients who receive standard-dose chemotherapy experience some degree of cognitive dysfunction....Patients may experience cognitive changes at any point during or following chemotherapy, and these changes may be short-lived, persist indefinitely, or have a delayed onset. Deficits can range from subtle to profound, but even slight changes can have a significant impact on everyday functioning. Most commonly affected are working memory, attention and concentration, information processing speed, reaction time, visuospatial ability, and executive function. Patients can be particularly distressed when their ability to organize and plan multistep tasks is impaired;" 


Other good references are:

"Chemotherapy-related cognitive impairment (CRCI) is a distressing side effect of cancer therapy and can persist beyond the duration of treatment in the majority of patients. CRCI is defined as cognitive decline experienced by those undergoing treatment of their cancer with chemotherapy. It is often referred to as 'chemo brain' or 'chemo fog' and for some it becomes the most troublesome survivorship issue faced. Most describe it as being unable to remember certain things and having trouble finishing tasks or learning new skills . The American Cancer Society defines CRCI as: forgetting things that you usually have no trouble recalling; trouble concentrating, remembering details, multi-tasking, and remembering commonwords; and taking longer to finish things.Cognitive impairment in gynecologic cancers: a systematic review of current approaches to diagnosis and treatment..

"The women exposed to chemotherapy performed significantly worse than the reference group on cognitive tests of immediate (P = .015) and delayed verbal memory (P = .002), processing speed (P < .001), executive functioning (P = .013), and psychomotor speed (P = .001)....Survivors of breast cancer treated with adjuvant CMF chemotherapy more than 20 years ago perform worse, on average, than random population controls on neuropsychological tests. The pattern of cognitive problems is largely similar to that observed in patients shortly after cessation of chemotherapy. This study suggests that cognitive deficits following breast cancer diagnosis and subsequent CMF chemotherapy can be long lasting." Neuropsychological performance in survivors of breast cancer more than 20 years after adjuvant chemotherapy.