When we tell people that we do research on the cognitive effects of breast cancer and its treatments, we often hear, “Oh, I didn’t know that happened.”  Many people, including patients themselves, are surprised that abilities like memory and focus can be affected by breast cancer treatments and there are so many unanswered questions within the breast cancer community. We were inspired to enter this field and shed light on ‘cancer-related cognitive impairments’ by talking to the patients themselves, in order to help answer their questions of why and how impairments occur, who is at risk, and most importantly, are they reversible or treatable?

Here we will try to address some of these common questions about cancer-related cognitive impairments. We are clinician scientists (Ashley is a nurse and Kathleen is a neuropsychologist) who have been studying breast cancer-related cognitive impairments for over a decade. Together, we strive to advance the science related to how we can effectively assess cognitive functioning and how to improve impairments for breast cancer patients and survivors.

What are cancer-related cognitive impairments (CRCI) and when can they occur?

While there is no strict definition of CRCI, the field tends to think about CRCI as cognitive changes that occur during breast cancer treatment and persist for some time after. We often hear from patients that they are confronted with new challenges in day to day life such as trouble coming up with names, or remembering words (feeling it’s on the “tip of the tongue” but never comes); they might feel their thinking is slower or muddy and can’t hold as much in their mind as they used to. Some patients describe feeling overwhelmed and losing the ability to multitask effectively, "dropping the ball” more at home or at work, or forgetting what they went into a room to get.  Sometimes these changes can also be really hard to describe, the person may just feel like they are not themselves.

You may have heard the terms ‘chemo brain’ and ‘chemo fog’ to describe the changes in cognitive functioning that people experience when undergoing breast cancer treatment, especially chemotherapy. Even though these cognitive changes are most commonly linked to chemotherapy, we now know that these issues are not only due to chemotherapy – research has shown that the cancer itself, radiation, surgery, and hormonal therapies— can also impair brain processes and cognitive functioning.  It is so important to recognize that these problems can happen to women at any stage of their cancer journey and with different types of treatment – that is why we prefer to use the term “cancer brain” or cancer-related cognitive impairments (CRCI). 

How do CRCI present across the breast cancer care continuum?

Sometimes cognitive changes can emerge around the time of diagnosis, even before starting breast cancer treatments (approximately 30% of newly diagnosed breast cancer patients). This can be especially distressing or challenging within the context of facing a serious diagnosis, navigating a new healthcare environment, and meeting a care team that will determine the plan of treatment. CRCI are most common during breast cancer treatments, with as many as 78% of women noticing some changes in their memory or thinking.  For most of these women, however, the “fogginess” gets better after treatment ends.  However, approximately 25% of women continue to experience cognitive problems well after treatment ends. Sometimes these issues are not even noticeable during treatment, but only when patients return to ‘normal’ environments and are confronted by challenges they didn’t have before. We often hear that people notice their CRCI first when they return to work and find they aren’t able to do their job exactly the same way they used to before their experience with cancer.

People don’t always know about the possibility of developing CRCI , so it can be really scary when someone experiences cognitive changes that they weren’t expecting. CRCI are “invisible” and many times family, friends, co-workers, even medical providers don’t see the changes that are very real for the person experiencing them. This is why it’s so important to get the word out that CRCI are in fact very real and not uncommon among cancer survivors, that a person experiencing these issues is far from alone.  

Do cognitive impairments get better or worse as time goes on, and do they increase the risk of developing dementia later in life?

Another important message is that there are evidence-based ways to cope with cognitive changes and even improve or optimize brain health.  For some, these issues get better over time with or without treatment and become no longer noticeable.  Others develop ways to cope with these changes that make them less bothersome.  Critically, though, CRCI are not the same as dementia and so far research has not definitively found that CRCI puts a person at greater risk for dementia later in life, but this is still being actively studied. 

What causes cognitive impairments for those diagnosed and treated for breast cancer?

We want to really stress that CRCI are not caused by one thing. There are several levels of causes that contribute to CRCI occurrence, persistence, and improvement/decline. This is also why CRCI don’t look like one thing, but can be experienced as different symptoms.

Breast Cancer and Treatment Level: 

• Chemotherapy: A large body of evidence supports that chemotherapy treatment for breast cancer is associated with an increased risk for CRCI along with structural and functional changes in the brain. 

• Breast Radiation: Radiation to the breast and chest wall can activate inflammation and oxidative damage throughout the body that can impact brain functions and cognitive processes.

• Surgery: Undergoing general anesthesia for any surgery is associated with risk for cognitive impairments. Many times, breast cancer treatment and reconstruction involve multiple surgeries. 

• Anti-estrogen Therapies: Estrogen can play a role in cognitive functioning and is also neuroprotective. There are also parallels between CRCI and menopause related cognitive changes, however it is still unclear how much anti-estrogen therapies contribute to CRCI.

• Breast Cancer: CRCI can present before the start of any breast cancer treatment, so it is likely that the pathology of the cancer itself and/or the extreme psychological stress of diagnosis play a role.  

Individual Level:

• Comorbidities: Chronic conditions including diabetes, autoimmune conditions, cardiovascular disease, anemia, liver disease, and mental health conditions can negatively impact cognition. Some research suggests that those with more comorbidities are at greater risk for CRCI.

• Genetic predispositions: Genetic links have been made to cancer brain including inherited genes (e.g., the APOE gene) and genes that are involved in repairing cells in the body, including neurons.

• Oxidative damage/Inflammation: Exposure to environmental toxins and stressors and can damage DNA structures.  Evidence supports that oxidative stress and damage occurs in breast cancer patients. Oxidative damage occurs on a cellular level and involves a buildup of oxygen reactive species (this occurs from environmental stressors such as UV light, pollution, toxins, etc.) that the body cannot effectively detoxify. This accumulation of oxygen reactive species then negatively interferes with normal biological processes and oxidative damage has been linked with other neurologic disorders such as Alzheimer’s and Parkinson’s diseases. Also, our immune systems are responsible for repairing damaged neurons in the brain. Breast cancer patients and survivors often have higher levels of inflammation compared to those without cancer. Studies in both animals and humans have shown that persistent inflammation can lead to cognitive deficits. Inflammation has also been linked to other symptoms in cancer survivors such as fatigue, depression, and sleep disturbance.

Situational/Contextual Level:

• Stress, Distress, Pain, Sleep. Many situational circumstances can either enhance or hinder our cognitive abilities. High levels of stress or distress (extreme feelings of anxiety or depression), chronic or acute pain, and lack of quality sleep are not uncommon among cancer survivors - and can all negatively impact cognitive abilities. Improving sleep quality starts with sleep hygiene. Learn more about how to optimize your sleep hygiene. 

• Social Support and Connection. There is a strong connection between social bonds, interpersonal connections and healthy brain functioning. Humans have evolved as social beings, and unfortunately today, most people regularly experience loneliness and social disconnection. This has been referred to as a ‘loneliness epidemic’ which is having broad negative effects on health including brain health.

• Lifestyle behaviors. Behaviors that make our overall health better or worse also impact brain and cognitive health. Decreasing health risky behaviors, especially smoking and alcohol use; and increasing healthy behaviors like physical activity, a diet rich in nutrients and antioxidants, good sleep hygiene, and stress management, will bolster cognitive functioning. 

What are evidence-based treatments that can optimize cognitive health and functioning during or after breast cancer?

Cognitive Rehabilitation/Training: Cognitive rehabilitation typically refers to a clinic-based, therapeutic program aimed to improve cognitive abilities, functional capacity, and real-world skills (typically a neuropsychologist, psychologist, speech and language pathologist, or occupational therapist). Cognitive training tends to focus on independent cognitive skills practice. Cognitive training programs are widely available, relatively inexpensive, and allow for remote administration with improved feasibility and access. Studies show that cognitive rehabilitation can improve memory, processing speed, and executive functioning in some cancer survivors. Evidence on the effectiveness of cognitive training is mixed, but some studies demonstrate cognitive enhancement.

• Here are several platforms that may assist with cognitive training:

• Brainhq.com

• Lumosity

• Mindgames.com

You can also search for cognitive rehabilitation centers or therapists in your area. Here is a cognitive rehabilitation center based in California, that also does virtual visits.

• Exercise and Movement: Exercise and physical activity, especially cardio/aerobic activity, are associated with improved cognitive function in both human and animal studies. There is growing evidence that exercise can improve cognitive function in healthy older adults and adults with cognitive impairments, and some studies have shown that exercise is beneficial to cancer survivors. Regular exercise improves brain health and helps with other contributing factors like sleep and emotional regulation. Read more about exercising after cancer guidelines from the American Cancer Society. 

• Manage Stress and Increase Coping Skills: The negative impact of high levels of stress on the human body and overall health is well known. Experiencing stress is part of everyday life, however, there are ways to both reduce overall stress and to adapt one’s reaction to stressors leading to overall better coping. Research supports many ways to reduce and/or cope with stress in a positive way, such as cognitive behavioral therapy, meditation, mindfulness training, and engaging in healthy behaviors and hobbies. Increasing self-kindness can also be an effective way to help manage stress, taking the time to appreciate our accomplishments, being gentle with ourselves when we make mistakes, even just telling ourselves “it’s ok, it will be ok” when faced with intimidating challenges. 

• Listening to Instrumental Music: Music therapy is recommended for anxiety and mood disturbance for cancer patients. Intentionally listening to music can improve mood, emotional regulation, psychological outcomes, and cognitive outcomes. Listening to music can be relaxing and is pleasurable for most people. Our lab has shown that regularly sitting and listening to music without lyrics improves cognitive functioning for cancer survivors. Music therapy may be even more advantageous for improving cognitive functioning. Music therapy involves working with a trained music therapist who asks you questions and tailors the therapy to your unique needs. Learn more about these findings from Henneghan lab in Dr. Henneghan’s podcast interview.

• Meditation and Attention Training. Various types of meditation and mindfulness have been used to reduce cognitive problems after cancer treatment. These are practices that increase awareness of one’s body, mental state, and surroundings in the present moment. Mindfulness practice can serve as training for attention and has been the most effective method to improve attention in cancer survivors. Other types of meditation including Kirtan Kriya, Tibetan Sound, and Qigong have also demonstrated improvements in global cognitive functioning, verbal abilities, and memory in breast cancer patients.

• Integrative Therapies and Practices. Several studies have tested yoga for improving CRCI. While it is not known how yoga improves cognitive function, it is likely a combination of things (breathing, physical activity, mindfulness) that collectively improve brain and cognitive functioning. A few studies have looked at using either acupuncture or acupressure to improve cognitive functioning after cancer treatment. Both therapies are provided by a trained professional and have been deemed “safe”.

• Compensatory Strategies. Compensatory strategies are workarounds or detours for cognitive tasks. For example— if you used to be able to attend a meeting and remember all of the points you were going to make, and now you can’t do that, instead you would make a list of the points you’d like to make and have it in front of you in the meeting to reference. Other examples include:

• Using external aids (e.g., smartphones or day planners) to organize, keep track of to-do lists, and set alarm reminders

• Breaking down tasks into smaller, manageable steps

• Keeping a notebook handy to write things down as they come up or use voice recording functions on a smartphone

• Asking for feedback when talking with others, e.g. “Did I tell you this already?”

• Minimizing distractions in your workplace – closing doors, turning off ringers and email when possible

• Repeating key points when talking with others to make sure you get the gist of what they are saying

• Being patient with yourself and allowing more time to complete tasks than you used to

A note about compensatory strategies: we are often asked by patients whether using reminders and relying on the above strategies is actually harming their brain function, or whether they should be challenging themselves more. The goal of compensatory strategies is to remove challenges and make day-to-day functioning easier. There are plenty of ways to exercise our brains – using these strategies doesn’t take away exercise, but does hopefully increase ease in day-to-day life. 

There are a growing number of medical professionals available to help assess and treat CRCI, we would encourage everyone to talk to their local treatment teams and communities to find more support if they are experiencing these challenging symptoms.

CONCLUSION

Much like you are unique, the cognitive symptoms you may be experiencing along with the underlying biological mechanisms at play are also unique. Unfortunately, there’s no one-size-fits-all treatment for CRCI, but there is certainly hope that things can improve. If you are experiencing CRCI, we recommend first monitoring and tracking patterns in your cognitive functioning— when are you functioning your best? What makes your symptoms worse? Are there certain times of day, days of the week, environments, situations, or circumstances that help/or hurt your cognitive functioning? The more you understand your own cognitive patterns, the better you will be able to manage them. We recommend picking an intervention/activity that sounds fun or interesting and try it for a month or two (i.e., self-experimenting). If you don’t notice any improvements consider increasing the amount, or ‘dosage’, or trying another intervention.

If you are facing CRCI, know that the symptoms we’ve outlined above are common among those being treated for breast cancer, and that you are not alone.  For most, CRCI will resolve within the first year of completing chemotherapy and radiation. For those who have persistent CRCI, there are healthcare providers who can help and evidence-based interventions to improve cognitive functioning.  Also, CRCI is an active field of research, we and many others are conducting studies to learn how we can reduce and ultimately prevent CRCI.

The Henneghan Lab is currently seeking several more breast cancer survivors to participate in a study funded by the National Institutes of Health assessing the impact of cognitive changes on everyday life following breast cancer treatment. Learn more and enroll.

Ashley Henneghan, PhD, RN, FAAN

CONTRIBUTOR

Associate Professor
School of Nursing
University of Texas at Austin
ahenneghan@nursing.utexas.edu

As a nurse, Dr. Henneghan's clinical experience has focused on alleviating unwanted symptoms and optimizing wellness for persons diagnosed and treated for cancer. Her research is aimed at defining, treating, and ultimately preventing cognitive and psychosocial symptoms in cancer survivors. Her lab, Henneghan Lab: Cognitive Health Initiative for Cancer Survivors, has several active studies that are currently enrolling participants. To learn more about these studies or access resources through her lab, please follow the link.

Kathleen Van Dyk, PhD

CONTRIBUTOR

Assistant Professor, Dept. of Psychiatry 
Division of Geriatric Psychiatry 
University of California, Los Angeles
Semel Institute for Neuroscience & Human Behavior 
David Geffen School of Medicine
kvandyk@mednet.ucla.edu

Dr. Van Dyk is a clinical neuropsychologist and researcher whose work has focused on aging and supporting cognitive health in cancer survivorship. Because of her clinical work with patients with CRCI, her research aims at understanding risk for cognitive decline, applying the most useful assessment methods to help understand the nature of cognitive problems, and how to develop effective support plans for patients with CRCI. 

Opinions expressed by the identified author in this blog post are their own and may not represent the views of the Keep A Breast Foundation or its management. Information found on the KAB website is for educational and informational purposes only and does not constitute medical advice. You are advised to consult a medical professional or healthcare provider if you are seeking medical advice, diagnoses, or treatment.

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