What is Chemobrain?
First, let’s clarify terminology: “Chemobrain” is often used in everyday language to describe cognitive changes (e.g., memory, thinking, or attention processing) due to cancer treatment that significantly interfere with an individual’s quality of life. This term is frequently used. But it's not necessarily the best way to define what oncology professionals refer to as cognitive changes potentially related to the cancer experience.
Terms such as “chemobrain” or “chemofog” are less preferred. This is because cognitive changes can be related to sources other than chemotherapy alone. For example, previous research has suggested that there are several other factors that can potentially influence cognition. These include hormone therapy, corticosteroids, other medications, and even radiation (especially in those with metastatic disease to the brain and central nervous system). In addition, pain, fatigue, sleep problems, stress and emotional changes can all affect cognitive functioning or thinking skills. For this reason, much of the field is moving to using terms such as Cancer Related Cognitive Dysfunction (CRCD) or Cancer Related Cognitive Impairment (CRCI).
What Does it Look Like?
In my professional experience, I have had patients report concerns such as:
- I can’t remember details of conversations I just had
- It’s much harder for me to keep track of my ‘”to-do”s each day
- I’m having a difficult time finding the word that I want to say when I’m talking to someone
- It takes longer for me to respond when someone is talking to me
- I’m having a difficult time focusing on the material when I read
Who Is Affected?
Much of the previous research in cognition in adult oncology has been conducted with individuals with breast cancer. Previous work suggests that up to 75% of patients with cancer experience cognitive impairment at some point during treatment. However, only 15% to 35% of cancer survivors experience cognitive problems in the months to years that follow the end of treatment. This means that although many individuals may experience cognitive changes initially, these changes tend to resolve for most people within 12-18 months after treatment ends. And they do not have lasting effects.
Why Does Chemobrain Happen?
The underlying causes of cognitive changes in the setting of breast cancer treatment are still being explored. Healthcare providers, scientists and survivor’s themselves observe that not everyone treated for breast cancer experiences cognitive changes, let alone changes that last long after treatment ends. One of the current goals in the field is to understand why there are such different outcomes given there are likely multiple factors that contribute to the individual’s experience of these changes. More recently, researchers are studying the role of genetics and its potential influence on differing cognitive experiences. In addition, researchers are considering potential pathways that contribute to the cognitive changes, including aspects of the body’s natural inflammatory response. It will likely take some time before we understand all the factors that contribute to cognitive changes.
What Can I Do?
Individuals may report different types of cognitive changes that make it difficult to accomplish daily life activities. These include quickly forgetting information and becoming more easily distracted. Or having difficulty verbally expressing themselves because they can’t find the word they want to say. If you have experienced these types of challenges and find they often interrupt your ability to get things done, you may consider the following:
Basic Self-Care:
We all know that good nutrition, getting a good amount of sleep and regular exercise are all important, and this is especially true for breast cancer survivors who may be experiencing cognitive changes. Maintaining these health routines is important for overall physical and mental well-being. They can also go a long way in supporting cognitive health, as well.
Practice Good Cognitive Habits:
These may include starting certain routines you haven’t used in the past. Use phone apps, a daily organizer or calendar alarms to remember information you used to “mentally track” before. These types of tools are not a “crutch”. Using them doesn't mean that you'll never get better. It just means you're allowing your brain to use helpful resources which may keep you from feeling mentally stressed or overwhelmed. They're the best way to support your cognitive function during this part of your journey. Other good cognitive habits include keeping your mind mentally active through activities, reading enjoyable material more often, playing games that make you think (e.g., bridge, chess, board games) and reducing multitasking. Our brains weren’t meant to juggle multiple challenging tasks all at one time. Give yourself the time to slow down. And try to focus on one thing at a time (or as few as possible!).
Know When to Talk to Your Medical Team:
Some individuals will go on to experience cognitive changes for a longer time (e.g., more than a year or so after treatment ends). If you feel this is happening to you, it may be helpful to talk to your oncology team. They may recommend further assessment of these concerns with a neuropsychologist (a professional who can conduct a comprehensive neurocognitive assessment). Not all cancer centers have this specialty. But other services, such as Occupational Therapy or Speech Therapy can sometimes provide brief cognitive screening and cognitive rehabilitation. Cognitive rehabilitation intervention provides strategies you can use in daily life to manage your cognitive challenges. Other services, such as Psychiatry or Neurology may provide recommendations for medication intervention if necessary. It is important to talk to your oncology team for specific information about what types of services are available at your treatment center.
Finally, it is important to note that your experience of cognitive changes doesn't mean you have dementia or some other neurodegenerative disorder. They are two very different things. Talking with a professional like those mentioned above can help you determine the difference. Know that more than likely, you will only experience these challenges for a while, with every hope of them getting better not too long after treatment ends.
Natalie Kelly, Ph.D., ABPP-CN is a Board Certified Clinical Neuropsychologist in the Department of Supportive Care Medicine at City of Hope. Her research interests include understanding cognitive concerns of the Adolescent and Young Adult population across cancer diagnosis groups. She is a featured speaker at the 2020 YSC Summit.
Resources:
ASCO Answers: Chemobrain https://www.cancer.net/sites/cancer.net/files/asco_answers_chemobrain.pdf
Your Brain After Chemo: A Practical Guide to Lifting the Fog and Getting Back Your Focus, by Dan Silverman, MD, PhD and Idelle Davidson
References:
Ahles TA, Root JC, Ryan EL. Cancer- and cancer treatment-associated cognitive change: an update on the state of the science. J Clin Oncol. 2012;30(30):3675-3686.
Ahles TA, Saykin AJ. Candidate mechanisms for chemotherapy-induced cognitive changes. Nat Rev Cancer. 2007;7(3):192-201.
Janelsins MC, Kohli S, Mohile SG, Usuki K, Ahles TA, Morrow GR. An update on cancer- and chemotherapy-related cognitive dysfunction: current status. Semin Oncol. 2011;38(3):431-438.
Schilder, C., Schagen, S. & van Dam, F, Effect of hormones and hormonal treatment on cognition. Cognition and Cancer; (2008). Cambridge University Press; New York, NY.
Wefel, JS., Collins, R., & Kayl, AE. Cognitive dysfunction related to chemotherapy and biological response modifiers; Cognition and Cancer; (2008). Cambridge University Press; New York, NY.
