Chemo fog is a condition related to degeneration in cognitive capacity, often reflected by impaired memory, difficulty in retaining attention, lack of speed in processing information and word fumbling. It is also referred to as cognitive deficit or chemo brain. Studies show that 75% of cancer patients across the world experience varied levels of cognitive impairment, and for almost 35% of these patients, this condition persists for months and even years following the treatment. According to an article in the ASCO Post, 20% to 30% of women experience prolonged deficits in cognition after breast cancer treatment.
Factors causing Chemo Fog in breast cancer patients
Studies from mid to late 1990s, which assessed cognitive function in breast cancer patients receiving chemotherapy, found that a large section of patients showed impaired cognitive performance during neuropsychological tests. This led to the belief that chemotherapy had detrimental effects on cognition capacity. However, since 2000, studies have delved deeper into this issue and revealed that cognitive impairment is not always associated with adjuvant chemotherapy but is also found in patients before its initiation. Furthermore, cognitive impairment is also found in women with breast cancer who did not undergo chemotherapy but were treated with hormonal therapies such as Tamoxifen, Anastrozole and Letrozole.
In fact, degeneration in cognition is now attributed to the toxic effects of chemo on neurological cells, changes in hormonal levels, clotting or inflammation in the brain, and genetic predispositions. Apart from these factors, surgery, radiotherapy, endocrine therapy, cancer related psychological burden and disease related life disruption also add to the overall worsening of this impairment. Due to high survival rates, breast cancer patients are likely to live with these problems for a considerable time and for some women the decrease in cognition can be persistent, lasting for decades after treatment.
Understanding Chemo Fog from Patient Experiences
For years, women suffering from breast cancer have been sharing their experiences in online forums in the form of millions of freely shared messages that provide information and support to other patients, care-givers and patient advocates. The conversations and messages shared over these sites are rich sources of information as to:
• how people feel about their symptoms of cognitive deficit
- what effect it has on their daily lives and
- how are they coping with these symptoms.
Scry Analytics used VoCP, (discussed below) as well as direct narratives from patients in online forums, they analyzed more than 5.5 million breast cancer messages written by 170,000 users in 22 unrestricted cancer forums. Analysis revealed the following interesting insights with respect to chemo fog in breast cancer patients.
The infographic given below shows that out of 5.5 million messages from various users, 21,890 messages mentioned cognitive deficit and out of these messages, the largest number reported symptoms associated with both hormonal and chemotherapy followed by those associated with chemotherapy alone.
For patients undergoing chemo and hormonal therapy together, their symptoms worsened after receiving hormonal therapy. Finally, most patients on chemotherapy attributed such symptoms to the use of Taxane.
Therapies discussed for mitigating chemo fog
Using VoCP, further analyzed messages to find references of therapies and drugs by patients that help with cognitive deficit and observed the following:
- 62 messages suggested cognition enhancing agents like Methylphenidate (Ritalin) or Modafinil (Provigil)
- 116 messages said that Vitamin B12 and B6 were useful
- 69 messages suggested the use of Acetyle-L- Carnitine
Suggested lifestyle changes for mitigating symptoms of chemo fog
It has been observed that patients with symptoms of cognitive deficit become overwhelmed when many things are happening simultaneously. They refrain from socializing, cannot concentrate for extended periods of time, and get distracted easily. For such patients it takes substantially more effort to complete a task, exacerbating all the other symptoms like fatigue and depression. While conducting this analysis of 21,890 messages, they found that along with taking supportive drugs for alleviating the signs of chemo fog, patients often resorted to various lifestyle changes that helped them.
Some popular methods reported by patients include:
- Using lists, calendars and planners to help focus and remember vital details
- Organizing their living and work spaces so as manage deficit in memory and cognition. Playing word games to alleviate symptoms and improve brain function
- Getting ample amount of sleep (at least 8 to 9 hours)
- Doing moderate exercise, such as walking, yoga or meditation
- Managing stress by listening to music, knitting or reading (as calming activities)
- Consulting a physician for symptoms of depression or anxiety as these may exacerbate chemo brain symptoms
- Improving nutrition and consulting a nutritionist to improve diet
- Taking multivitamin B complex and other similar supplements
- Increasing social activity
Factors that can aggravate symptoms of chemo fog
By analyzing these messages, they discovered that for breast cancer patients, in addition to the cancer treatment, the following factors can amplify their symptoms of chemo fog:
- Poor sleep
- Fatigue related to treatment
- Chronic stress
- Under-treatment or over-treatment of pain
- Depression and anxiety
- Lack of exercise or activity
- Poor nutrition
- Side effects of medicines for other conditions, e.g., nausea and sleep medicines
Cancer-related cognitive impairment is an important clinical problem that negatively impacts the quality of life of patients; this problem is becoming more acute since patients are now living longer. The analysis provided by Voice of Cancer Patients gives meaningful insights from patients’ point of view and sheds light on unresolved issues where more resources and research should be focused. Successful management is often hampered by the lack of pathophysiology of such symptoms, and a better understanding of this problem may lead to better treatment options.
Voice of Cancer Patients and Our methodology
Online healthcare forums contain millions of freely shared messages that are rich sources of patient data, which can be analyzed for understanding patients concerns. However, analyzing such information is difficult because this data is intrinsically unstructured. Furthermore, large volume of such data adds to complexity, making any meaningful analysis difficult. Voice of Cancer Patients (VoCP) uses parallel and distributed computing, Natural Language Processing, Machine Learning, and rule-based algorithms to process unstructured text and to extract various attributes of patients, drugs, regimens, side effects, and their supportive therapy. This platform also provides an interactive visualization interface that can be used to explore relations among various entities and extract meaningful insights. VoCP works as follows:
Portions of this article were originally presented as a poster in ASCO (American Society of Clinical Oncology) Breast Cancer Conference, September 2015. For additional research regarding Voice of Cancer Patients, contact: Dr. Sangeeta Aggarwal, Chief Medical Information Officer, Oncologist-Hematologist, Scry Analytics, Inc. Email: firstname.lastname@example.org or email@example.com
- Schagen SB, Wefel J S, “Chemotherapy-related changes in cognitive functioning,” can be found at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4041313/
- Ahles TA, Root JC, Ryan EL, “Cancer- and cancer treatment-associated cognitive change: an update on the state of the science,” J. Clin. Oncol. 30(30):3675-3686, 2012.