Exercise as it relates to Disease/The Benefits of Resistance Training in Breast Cancer Patients Receiving Adjuvant Radiotherapy
This wikibooks page is a fact sheet and analysis of the journal article 'Randomized controlled trial of resistance training in breast cancer patients receiving adjuvant radiotherapy: results on cancer-related fatigue and quality of life'. Statement: this wikibooks page has been created by u3084542 from the University of Canberra for an assignment for Health Disease and Exercise
Background to the Research
Breast cancer is a disease where abnormal cells in the breast tissue multiply forming malignant tumors. These tumors can then spread around the body via the lymphatic or vascular systems and if not detected or controlled, can result in death. One treatment option for breast cancer is radiotherapy, which is a specifically targeted treatment used after breast surgery. It uses a high energy beam to destroy any cancer cells that may still be in the remaining breast tissue following surgery and reduces the rate of re-occurrence. Breast cancer patients undergoing radiotherapy treatment commonly complain of moderate to severe fatigue, with some patients still experiencing fatigue up to a year after treatment ends. Patients commonly identify fatigue as one of the most distressing complaints, affecting their return to work and overall quality of life.
Incidence of Breast Cancer
- In Australia in 2012, breast cancer was the 2nd most commonly diagnosed cancer; 15,166 new cases diagnosed in 2012, Estimated 16,084 new cases will be diagnosed in 2016.
- In Australia in 2013, there were 2,892 deaths from breast cancer; majority of these were females; 2,862 females and 30 males.
- Australians diagnosed with breast cancer have a 90% chance of surviving the following 5 years.
With the incidence of breast cancer increasing yearly, more people are suffering with fatigue related symptoms. Increasing evidence is emerging that exercise can be an effective treatment for cancer-related fatigue, however there is little research on the effects of exercise in patients undergoing adjuvant radiotherapy. This study aims to begin to fill this knowledge gap.
Where is the Research from?
This research came from the University of Heidelberg Medical Centre, with the study being approved by the University of Heidelberg ethics committee. The authors have declared no conflicts of interest in this study, with funding supported by the Interdisciplinary Research Funding Program of the National Center for Tumor Diseases, Heidelberg, Germany.
What kind of Research was this?
This study is a prospective, randomised controlled trial (RCT).
RCTs are an effective study design used to measure the effectiveness of an intervention. Participants are randomly allocated to two or more different groups. One group participates in the ‘standard’ treatment becoming the ‘control group’, and other group/s receive the interventions to be trialed. At the end of the trial the effects of the interventions are compared between groups and the control.
This study involved 160 patients with breast cancer in stages 0-III during adjuvant radiotherapy. Participants were randomised into either the experimental group which participated in progressive resistance training, or the control group which participated in relaxation therapy. Both groups completed a 12 week supervised program consisting of two one hour sessions a week, both interventions were group based. The primary outcome measures included:
- Cancer-related fatigue - assessed with the Fatigue Assessment Questionnaire. A 20 item self-reported questionnaire validated in the German population
- Quality of life - using the 30 item self-reported questionnaire of the European Organization for Research and Treatment of Cancer.
Secondary outcome measures included depressive symptoms and muscle strength (isokinetic and isometric) for upper and lower body muscle groups. Outcome measures were recorded prior to starting radiotherapy treatment, post-radiotherapy (at 7 weeks) and post intervention (week 13) in both groups. Any adverse events were recorded by the participant or the observing therapist.
Table 1: Strengths of the Method
|Strengths||What it Means and Why it’s Important|
|Randomisation||- Successful and there is no significant difference in characteristics between the groups at baseline
- Ensures all differences in results at the end of the study are actual differences from the effect of the intervention
|Intention to Treat||- Even though participants drop out of the study, all participants are analyzed in the groups they are initially assigned to, regardless of whether they received the intervention or not
- Increases the reliability and validity of the results produced
|Inclusion and exclusion criteria||- Helps determine how applicable the results are in the wider population|
Table 2: Weaknesses of the Method
|Weaknesses||What it Means and Why it’s Important|
|Blinding||- When the participants don’t know which intervention they are receiving. There is no mention of patient blinding in this study
- Knowing which group a participant is in can cause an imbalance in the patient’s perception of the treatment effect. Significant in studies that use self-reported outcome measures like this study, double blinding of participants and practitioners is needed to avoid bias
|Primary outcome measures are self-reported||- Both major outcome measures are self-reported, which has the potential to introduce bias and impact the results as it is easy for patients to under/overestimate how they are actually feeling|
- Total cancer related fatigue in particular physical fatigue, significantly reduced in the resistance exercise group, compared to the relaxation control group where there was no significant change.
- The exercise group showed significantly larger improvements in quality of life in role function and pain aspects, compared to the control group.
- Significant improvements in muscle strength were evident in the exercise group only.
- No injuries or severe adverse events were reported in either group throughout the study.
The authors of this study used a p-value of <0.05 to determine when the difference between groups showed statistically significant results. It is mentioned throughout the results when groups differed post intervention, but not to a significant level. This allows the reader to determine the implications and effect size of the findings.
Conclusions from the Research
There is emerging evidence that resistance training starting the day of radiotherapy is effective in reducing cancer related fatigue and improving some aspects of quality of life in breast cancer patients undergoing radiotherapy. It is shown to be a safe and feasible intervention.
The results from this study are in line with current literature. A review article released this year, investigated the effects of physical exercise during adjuvant breast cancer treatment on the physical and psychosocial dimensions of cancer related fatigue. Results showed that for breast cancer patients undergoing adjuvant treatment, physical exercise can have beneficial effects on general fatigue and physical fatigue and can help improve activity participation and motivation. Results are increased when exercise is in a supervised group format. Further research into this area with appropriately designed studies is needed to build on, and strengthen these findings.
Breast cancer patients undergoing radiotherapy interested in starting resistance training should consult with their oncologist and doctor before commencing training. This will ensure they are seen by an appropriately trained health professional who has knowledge in this area to prescribe, teach and monitor the patient's program and their situation.
Some caution should be taken when interpreting and comparing an individual's results to the results presented in this study given the potential for bias, introduced by weaknesses in the method. Individual results from resistance training can vary.
Further Information and Resources
The following links may be useful for further information on breast cancer, radiotherapy, and fatigue:
- Steindorf K, Schmidt M, Klassen O, Ulrich C, Oelmann J, Habermann N et al. Randomized, controlled trial of resistance training in breast cancer patients receiving adjuvant radiotherapy: results on cancer-related fatigue and quality of life. Annals of Oncology. 2014;25(11):2237-2243.
- Australian Institute of Health and Welfare & Cancer Australia 2012. Breast cancer in Australia: an overview. Cancer series no. 71. Cat. no. CAN 67. Canberra: AIHW
- How Radiation Therapy Works [Internet]. Breastcancer.org. 2016 [cited 20 September 2016]. Available from: http://www.breastcancer.org/treatment/radiation/how_works
- Van Vulpen J, Peeters P, Velthuis M, van der Wall E, May A. Effects of physical exercise during adjuvant breast cancer treatment on physical and psychosocial dimensions of cancer-related fatigue: A meta-analysis. Maturitas. 2016;85:104-111.
- 1. Australian Government. Breast cancer in Australia (AIHW) [Internet]. Aihw.gov.au. 2016 [cited 20 September 2016]. Available from: http://www.aihw.gov.au/cancer/breast/
- Hoffmann T, Bennett S, Del Mar C. Evidence-based practice across the health professions. 2nd ed. Sydney: Churchill-Livingstone; 2013.
- Bereznicki L, Castelino R. Understanding randomised controlled trials. Australian Pharmacist. 2013 Apr;32(4):71.