Foggy thinking after cancer treatment? “Chemobrain” only explains some of these difficulties, and scientists are working on ways to treat this symptom that can impact enjoyment of everyday life.
I have just spent a few inspiring days in Sydney’s glorious autumn weather attending my first ever International Cognition and Cancer Task Force (ICCTF) Conference. This group of welcoming and passionate cancer researchers and clinicians are particularly interested in how cancer and cancer treatments impact memory and thinking: a side effect reported by up to 75% of patients, and that can persist for months or even years post-treatment.
Not everyone experiences difficulties with their thinking associated with cancer and cancer treatment, and we cannot currently predict who will or will not. Some of the factors involved in determining who develops cognitive symptoms may include genetic factors (for example Dr Denise Correa from Memorial Sloan Kettering Cancer Centre discussed genetic associations her research group has been exploring), as well as factors associated with the cancer itself (as summarised by Dr Janette Vardy, University of Sydney). For those patients who do have difficulties, they are often subtle but important. They tend to impact speed of thinking, ability to multi-task, plan and organise, and memory, and patients often describe having to work harder to achieve the same outcome. Cognitive symptoms are important as they negatively impact quality of life and daily function, including the ability to return to work in the same capacity.
The research presented used many different scientific methods, ranging from preclinical work (mouse models of cancer), genetic studies, neuroimaging, the patient experience, and therapies to improve cognition. One of the main messages was that although the concept of “chemobrain” or “chemofog”, related to the acute effects of chemotherapy, has been recognised for a while, this cannot explain all of cancer’s cognitive effects. The preferred term is cancer-induced or cancer-associated cognitive impairment.
This concept solidified for me throughout the conference, but was particularly well illustrated in Dr Adam Walker’s (Monash Institute of Pharmaceutical Science) plenary describing the various mouse models his group have developed to investigate the influence of cancer on cognition. He noted that 20-30% of patients report cognitive impairment prior to treatment. Factors impinging on cognition at this stage may include the biological impact of the cancer itself, as well as stress and anxiety associated with a cancer diagnosis. Mouse models from his group support the role of the cancer itself in affecting memory and learning, even before the mouse starts to feel sick. He also noted that his group are investigating the impact of surgery on memory and thinking. In human studies, brain imaging is often used, and demonstrates changes associated with cancer and its treatment, with overviews of some of this work presented by Dr Daniel Silverman, University of California and Associate Professor Donald Mabbott from the Hospital for Sick Children, Canada.
Memory and thinking is impacted when we are stressed or worried, and when someone has cancer, they often will have increased stress, worry, and anxiety – both before, during, and after treatment. We also know that poor sleep impacts on our memory and thinking, and cancer survivors are 2-3 times more likely to have sleep issues than people who haven’t had cancer. Danielle Tometich, from Indiana University-Purdue University reported that up to 10 years post treatment, about a third of breast cancer survivors reported sleep difficulties. Thus researchers, such as Dr Lisa Wu from Northwestern University, are examining whether improving sleep might help improve thinking and memory. Fatigue, an extremely common symptom of cancer and cancer treatment, is associated with cancer survivors’ reports of difficulties with memory and thinking.
Thus, research is demonstrating that there are many factors, in addition to chemotherapy, impinging on thinking skills after cancer and cancer therapy. Many of these factors are things that psychologists commonly help manage, including stress, anxiety, fatigue management, and sleep hygiene (more on these in a blog coming soon). Furthermore, cognitive interventions such as learning specific memory strategies, can improve memory and thinking. Dr Haryana Dhillon (University of Sydney) provided a nice summary update of the recent evidence that cognitive interventions can help improve cancer-induced cognitive impairment, although more studies are needed. I am working with Professor Carlene Wilson and Dr Gemma Skaczkowski, from the Olivia Newton-John Cancer Wellness and Research Centre, to do some of this research, and we hope to trial the LaTCH memory management program (more about that in a future blog) in cancer survivors later this year.
Meanwhile, in my role at YCP, I am happy to see cancer survivors who have concerns about their cognition for a comprehensive neuropsychological assessment, including objective cognitive assessment and examination of contributing factors such as stress, anxiety, and fatigue. I also offer individualised intervention addressing any cognitive issues and other contributing factors, and group intervention may be available down the track. If you would like to enquire about an assessment or intervention, please contact us on 9429 0050. Referrals can be faxed to 03 8678 0645.