Clinical Update - Breast Cancer
Exercise for women being treated for early stage breast cancer
Commentary by Dr Helen Milne
The article
Mutrie N, Campbell AM, Whyte F et al. Benefits of supervised group exercise programme for women being treated for early stage breast cancer: pragmatic randomised controlled trial. Brit Med J 2007;334:517–24.
Reviewer
Dr Helen Milne, until recently, was the Women’s Cancer Coordinator at The Cancer Council Western Australia. She has recently relocated to Melbourne, Victoria. Dr Milne completed her PhD at the University of Western Australia on the effects of exercise on quality of life for breast cancer survivors.
Summary
Abbreviations
Confidence Interval (CI), Functional Assessment of Cancer Therapy – Breast cancer (FACT-B), Functional Assessment of Cancer Therapy – General (FACT-G), Functional Assessment of Cancer Therapy – General – Social domain (FACT-GS), National Health Service (NHS).
Study design
Two hundred and three women were recruited between January 2004 and January 2005 from three NHS oncology centres in Scotland and randomly allocated to either a 12-week supervised exercise program group (n=101), or a control group (n=102). The primary outcome was quality of life, as measured by the FACT-G questionnaire. Secondary outcome measures included the Beck depression inventory, the positive and negative affect scale, body mass index, seven day recall of physical activity, performance in a 12 minute walk test and score on a shoulder mobility test. Participants were assessed at baseline (n=203), 3 months (n=174, 86%) and six months (n=177, 87%). Analyses were by intention to treat.
Findings
There was no significant difference between the treatment groups in FACT-G scores (primary outcome). Women in the exercise group had significantly better scores than those in the control group for the: FACT-B subscale, positive affect scale, 12 minute walk, and shoulder mobility score at both assessments; for the number of minutes of moderate intensity activity per week at 3 months; and, in the FACT-GS at 6 months. Women in the exercise group also reported fewer nights in hospital (p=0.04) and fewer visits to their general practitioner (p=0.01) than those in the control group.
Conclusion
A 12-week supervised exercise program improved physical and psychological function, but not overall quality of life, in women being treated for early breast cancer.
Commentary
What does this article add to existing clinical evidence in this area?
The authors were interested in understanding whether a supervised group exercise programme had any positive functional or psychological benefits for women undergoing treatment for early stage breast cancer. Increasingly, the research is demonstrating that women who remain inactive during treatment and into the time after treatment has finished, report poorer quality of life outcomes compared with those who remain active throughout their cancer journey.1 As treatments improve, quality of life is becoming as important an outcome factor as quantity of life. Consequently researchers and health professionals are examining health behaviour choices such as exercise as a means for improving quality of life.
A number of recent meta-analyses as well as empirical studies have demonstrated the benefits of exercise on physiological and psychological function across a number of different cancer groups.2 Outcome measures have included global quality of life, fatigue, depression, physical and functional well-being, social factors, pain, and body image. Often quality of life research is conducted retrospectively relying on participant recall, although more recently, a number of randomised controlled trials have been conducted examining quality of life issues prospectively. However, this paper is unique in that the participants were followed-up at 6 months to determine any latent effects of an intervention and the authors were able to demonstrate that most of the significant effects observed at 12 weeks were maintained at 6 months with no reported adverse effects. The observed effect of the intervention at 6 months is of relevance given that the participants were still receiving adjuvant therapies that may have caused them to experience continuing side effects. The study demonstrated therefore that a short exercise intervention can have lasting benefits on quality of life in the longer term and therefore patients may not need to be in lengthy exercise programmes to derive positive health benefits.
How adequate was the methodology used in addressing the aim of the study?
The randomised controlled trial design adopted was effective at a number of levels. The authors were able to prospectively analyse exercise behaviour and quality of life rather than relying on biased recall methods which are often used in quality of life research. The sample size was large and seems representative of women being treated for breast cancer in Scotland. Good retention of participants and completion of study assessments was reported at both 3 and 6 months. A range of reliable, validated self-report measures were adopted including the FACT-B questionnaire which has been used effectively in previous quality of life research with breast cancer patients.3 The primary outcome of quality of life, as measured by the FACT-G questionnaire, showed no significant intervention effect. This may have been a consequence of the numerous aspects assessed by the FACT-G, including perceived effects on role, physical, emotional and social function, only some of which may benefit from exercise. The benefits of exercise may also have been obscured by the side effects of adjuvant therapy. Another reason may be the relatively short duration of the exercise programme (12 weeks).
As the authors did not differentiate between demographic or medical variables such as age, menopausal status or cancer stage, it is difficult to determine if the exercise programme was more effective for particular sub-groups of participants (eg pre-menopausal versus post-menopausal status).
The trial does however offer support for conducting shorter-term exercise programmes among groups of cancer patients especially since these populations are known to report reduced exercise levels throughout treatment4 and have difficulty adhering to a programme or report decreased motivations to exercise. Of importance, the authors acknowledge and discuss that they were unable to determine which factors specifically, within the group exercise setting, provided the most benefit to the participants.
What are the implications of this study for clinical practice in Australia?
Our knowledge of the significance of exercise as a means of not only improving immediate physical and psychological outcomes, but also, perhaps more importantly, as an effective means for reducing mortality for those survivors who remain active is increasing.5 Indeed, this study reinforces the results of previous work and supports participation in an exercise programme for women who are on average 6 months post-diagnosis, demonstrating that it is a safe and effective strategy for enhancing quality of life and psychological well-being. Exercise however is not included in routine clinical practice in Australia for people diagnosed with cancer. Most often, women are referred to a physiotherapist for advice about maintaining exercise mobility post-surgery or are encouraged to continue gentle exercises. Structured group exercise programmes may be advised but are often not available. This paper reinforces the need for exercise to be considered as part of cancer patients’ rehabilitation and to support cancer patients’ decision to be physically active during treatment. One of the difficulties of adopting exercise within clinical practice in Australia is that although exercise is effective, the optimal mode, duration and intensity of exercise will depend on each person’s circumstances and abilities.
References
1. Irwin ML, McTiernan A, Bernstein L, et al. Physical activity levels among breast cancer survivors. Medicine and Science in Sports and Exercise 2004;36(9):1484–91.
2. McNeely ML, Campbell KL, Rowe BH, et al. Effects of exercise on breast cancer patients and survivors; a systematic review and meta-analysis. Canadian Medical Association Journal 2006;175(1):34–41.
3. Courneya KS, Mackey JR, Bell GJ, et al. Randomized controlled trial of exercise training in postmenopausal breast cancer survivors: Cardiopulmonary and quality of life outcomes. Journal of Clinical Oncology 2003;21:1660–8.
4. Irwin ML, Crumley D, McTiernan A, et al. Physical activity levels before and after a diagnosis of breast carcinoma. The health, eating, activity and lifestyle (HEAL) study. Cancer 2003 97:1746–57.
5.Holmes MD, Chen WY, Feskanich D, et al. Physical activity and survival after breast cancer diagnosis. Journal of American Medical Association; 2005 293 (20): 2479–86.
Editor: Dr Karen Luxford, Deputy Director NBCC.
Editorial Committee: Mr John Collins - Surgeon,
Dr Sue-Anne McLachlan - Medical Oncologist,
Dr Sue Pendlebury - Radiation Oncologist,
A/Prof Martin Stockler - Medical Oncologist, Ms Jo Keyser - Specialist Breast Nurse, Dr Sally Meade - Breast Surgeon, Dr Warwick Lee - Radiologist, Dr Penny Schofield - Senior Research Fellow.
Disclaimer
Clinical Update - Breast Cancer is produced by the National Breast Cancer Centre (NBCC) and is intended to provide health professionals with timely expert commentary on new research in breast cancer. Commentaries included in Clinical Update - Breast Cancer do not replace recommendations included in NBCC clinical practice guidelines.
Information contained in Clinical Update - Breast Cancer is not intended to be used as substitute for an independent health professional's advice. The NBCC does not accept any liability for any injury, loss or damage incurred by use of or reliance on the information contained in Clinical Update - Breast Cancer. The NBCC develops material based on the best available evidence however cannot guarantee and assumes no legal liability or responsibility for the currency or completeness of the information.