Please can you explain why people with cancer often experience fatigue?
It is likely that there is more than one reason why people with cancer experience fatigue. The causes are likely to include side effects of the treatment that people are receiving for cancer as well as the direct effects of the cancer.
Other side effects of cancer such as nausea and reduced appetite may also cause poor nutrition that can increase a person’s feelings of tiredness. In addition patients may develop anaemia that can contribute to fatigue.
A diagnosis of cancer and the associated treatment can also cause a lot of distress and anxiety that may increase feelings of fatigue. It is likely that every patient will be affected differently and it is not always easy to identify a precise cause of a patient’s fatigue.
What are the main symptoms of cancer-related fatigue?
Cancer-related fatigue can affect a person physically which may prevent them from doing even the simplest tasks such as taking a shower or making a cup of tea. It may also affect them cognitively for example they may have difficulty remembering things or concentrating for even short periods of time.
Some patients will also experience emotional fatigue such as a lack of enjoyment or interest in usual hobbies or a high level of anxiety. Overall, fatigue is unique to the individual who is experiencing it and symptoms will vary from person to person.
How long does cancer-related fatigue tend to last?
For the majority of patients fatigue will reduce at the end of cancer treatment and will often disappear completely within a few weeks to months. Some people will continue to experience low levels of fatigue for several months following treatment and for a small number of patients a high level of fatigue can persist for years following treatment.
Why is it important to deal with cancer-related fatigue?
Fatigue can significantly impair a patient’s quality of life so it is important that it is managed effectively. In extreme case patients may even refuse to continue with their cancer treatment due to high fatigue levels. Fatigue can also impact upon a person’s ability to participate in their daily occupations which may include paid work.
What ways have people traditionally tried to overcome cancer-related fatigue?
In the past patients who reported fatigue were advised to rest. We now know that this is poor advice as it is likely to result in physical de-conditioning and further exacerbation of fatigue. It is therefore important that patients find a balance between physical rest and activity. This will however need to be tailored to each individual according to their level of fitness and the side effects of the cancer and its treatment.
Please can you explain what prompted your review into exercise and cancer-related fatigue?
When we carried out the original review in 2008 it was prompted by the general theory that long periods of rest would cause a person to lose general fitness and make any activities more strenuous.
In the earlier work we found that there was a general benefit of exercise in reducing cancer related fatigue. However, the findings did not tell us what type of exercise was best for reducing fatigue. In this update we wanted to find out what type of exercise was best for treating fatigue so that we could provide patients with more tailored support.
What did your review find?
We found that the best form of exercise for reducing cancer related fatigue was aerobic exercise. Examples of aerobic exercise include walking, cycling and jogging. The same benefits were not observed with strength training or other forms of exercise such as yoga.
The benefits of exercise were found both during treatment for cancer as well as after treatment had finished suggesting that patients should be encouraged to remain active at all stages of the cancer journey.
How did your updated review compare to earlier findings?
There were twice as many studies in the updated review compared to the original review so we can have more confidence in our findings. The new review also allows us to be more precise about the type of exercise that patients need to do in order to reduce fatigue.
Although the majority of studies were carried out on patients with breast cancer we also found that the benefits of exercise extended to other groups of patients with solid tumours such as prostate cancer.
Why do you think cancer patients benefitted from aerobic exercise and not from other forms of exercise?
Aerobic exercise works more muscles at one time and generally the larger muscle groups when compared to strength training. It also helps to improve cardiovascular fitness by making the heart and lungs work. It is possible that by maintaining a general level of fitness through aerobic exercise people are able to be more active with less effort.
Further to this the increased circulation associated with aerobic activities may help to remove toxic waste from the body that has arisen following treatment.
Finally aerobic exercise can reduce the levels of stress hormones such as cortisol and increase endorphin levels leading to increases in a patient’s sense of well-being.
What impact do you think your review will have?
It is hoped that the findings of the review will be used by health professionals in advising patients how they may be able to reduce their fatigue levels. It may also be used to reassure patients that doing physical activity following a cancer diagnosis is likely to be beneficial and that long periods of rest may be detrimental.
The review has also identified the need for further research that shows how physical activity programmes can best be tailored to the individual patient, for example, how long should exercise sessions last and how often should they take place.
Finally, it is hoped that more programmes will be developed internationally to help patients manage cancer-related fatigue and that the programmes will incorporate aerobic activity.
Would you like to make any further comments?
Before commencing an exercise programme it is important that cancer patients discuss their intentions with a health professional to ensure that they undertake safe and suitable activities. It is also important that exercise programmes are tailored to the individual and any increases in activity are undertaken gradually over a period of time.
Where can readers find more information?
Full Review: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006145.pub3/full
Featured Summary: https://www.cochrane.org/
Macmillan: http://www.macmillan.org.uk/Cancerinformation/Livingwithandaftercancer/Symptomssideeffects/Fatigue/Fatigue.aspx
About Dr Fiona Cramp
Dr Fiona Cramp is a Chartered Physiotherapist and completed her PhD at the University of Ulster in 2000. She subsequently worked as a Lecturer in Ulster before moving to the Northern Ireland Research Office to work as the Programme Manager for the Allied Health Professions.
She returned to academia in 2005 and currently works at the University of the West of England as an Associate Professor in Musculoskeletal Health. She is also the Director of Postgraduate Studies for the Faculty of Health & Life Sciences.
Her research is mainly in the area of physical activity interventions for people with long term conditions. Recently this has focussed upon physical activity to help manage fatigue in rheumatoid arthritis and cancer populations.
In the main, her research has used quantitative approaches although she works closely with qualitative researchers. She has contributed to the development of patient reported outcomes and also has experience of conducting Cochrane systematic reviews.
She has received in excess of £1.5m in grant income, co-authored over 70 peer reviewed publications and supervised 7 PhD students to successful completion.
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