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Exercise as it relates to Disease/Recovery from cancer, the effect of physical activity on patients quality of life

A critique of the journal article Effectiveness of Physical Activity on Cardio-respiratory Fitness and Health- Related Quality of Life in Young and Middle- Aged Cancer Patients Shortly After Chemotherapy-L Thorsen et al 2005.[1]

BackgroundEdit

Cancer is a debilitating disease. Diagnosis and treatment places great physiological and psychological stress on the individual.[1] Much research has gone into improving health-related quality of life (HRQOL) in patients, especially surrounding physical activity[2][3].

Side effects of treatment[1][4]Edit

Physical Physiological
Fatigue Fatigue
Reduced Cardio-respiratory function Anxiety
Muscle-loss Depression
Chronic pain
Weight change


Specifically, this research focused on the effect of a flexible training intervention on patients immediately post treatment. Previously research, primarily focused on closely structured programs, have indicated an improvement of physical function, mental distress, and fatigue[2][3]. Utilising a flexible program was hypothesised to improve psychological aspects in patients as they were theorised to be more enjoyable to perform[1]. Primary focus was placed on fatigue as it was expected to have significantly improvement due to flexibility of the program.
Over 100,000 people were diagnosed with cancer last year in Australia, finding the best method on improving HRQOL following treatment will benefit a great number of people[5].

Location of researchEdit

This study was primarily conducted through the Department of Psycho-social Oncology and Rehabilitation in the Norwegian Radium Hospital-Lene Thorsen, Sophie D. Fosssa. Other supporting institutions:

  • University of Oslo-Eva Skovlund
  • Norwegian university of sport and physical education-Sigmund B. Stromme
  • Oslo city hospital-Alv A. Dahl

At the time of publication, authors had varying levels of experience in the field. Three of them had participated in over 20 studies in relating fields; the other two had little experience. The study was published in the Journal of Clinical Oncology. A highly reputable journal that has been running for 36 years. There seemed to be no bias within the article; the authors indicated no potential conflicts of interests[1].

Type of researchEdit

The study conducted was a randomised control trial. Participants were randomly split into an intervention or control group. Results were compared between the two groups[1]. This is the gold standard of research.

MethodEdit

Patients included in the study were recruited from either of the two university health clinics in Norway, the Norwegian Radium Hospital, or the Oslo city hospital. They all had undergone chemotherapy for malignant lymphomas; breast, gynaecologic, or testicular cancers; and were between ages of 18-50. No evidence of the disease was present at initiation of the intervention, and all treatment had been discontinued approximately one month before the study[1].

139 patients agreed to participate. They were randomly split into two groups; intervention and control. Baseline measurement were taken at initiation of the study, then repeated fourteen weeks later. 18 pulled out during the intervention period[1].

Table 2 - Measurements[1]Edit

Test What it is What it assessed
Astrand-Rhyming bicycle ergometer test Sub maximal aerobic fitness test Peak VO2max (cardio-respiratory fitness)
EORTC QLQ-C30* Questionnaire comprised of 5 functional scales, 3 fatigue scales, and 6 single items assessing symptoms commonly found in cancer patients; scale 0-100 (higher score = better) Overall health related quality of life (HRQOL)
HADS** Self-rating scale determining levels of anxiety and depression in ill patients; scale 0 - 21 (lower score = better) Mental distress

*European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire
**Hospital Anxiety and Depression Scale

Intervention [1]Edit

Intervention group received:

  • Written information on the simple principles of training physiology
  • Supervised home-based flexible program design by an instructor
    • Minimum, two 30 minutes sessions (14 weeks)
    • Activities chosen by patient
  • Advised to maintain intensity between 13-15 on the Borg scale of perceived exertion
  • Control group advised to behave as per normal

LimitationsEdit

  • Use of indirect CRF test; direct VO2max test more accurate
  • Patient selection and difficulty of the method; patients with low CRF, HRQOL, or high mental distress refused to participate and/or dropped out of the study. Those that participated had higher CRF and lower depression levels than average in a similar population.
    • Due to the selection method, patients in the control group were more inclined to exercise compared to the same population. In the end, both intervention and control group averaged the same minutes of exercise per week.
  • No differentiation between acute and chronic fatigue.

ResultsEdit

Inter-group differences between pre & post intervention scores [1]Edit

Factor Intervention/control score difference Significant difference
CRF, VO2max +3.10 Yes
Anxiety +0.52 No
Depression +0.41 No
Physical function -2.03 No
Emotional Function -4.74 No
Fatigue +9.51 Yes
Quality of life -1.03 No
  • Improved VO2max
  • Increased fatigue
  • Slight increase in mental distress & emotional function scores (not significant)

Due to the fact the groups participated in the same amount of exercise, researchers concluded the improvements in V02max were due to implementation of a greater variety of activities in the intervention program[1]. However, I believe the magnitude of increase is slightly overstated. Average VO2max was significantly lower at initial testing in the intervention group; 28.2/31.7 O2.kg-1.min-1, and increases were therefore easier to attain.
Rise of fatigue in the intervention group was most likely caused by the timing of the study. As it was immediately after a strict chemotherapy course, participants were at their worst physical condition[3]; additional burden of a strict training program increased their fatigue above those in the control group.

ConclusionsEdit

A flexible physical activity program improves CRF for cancer patients immediately following treatment. This is strongly backed by most other research showing benefits of exercise on cancer patients during and post treatment[3][4]. However, exercise shouldn't be implemented immediately following treatment as it can place increased burden on the patient causing fatigue. Allowing some time for natural recovery before initiating a program should reduce this risk.
A slight decrease in physical and emotional function as well as increase in mental distress was possibly shown yet, other studies have produces a great variety of results in this area[4]. Further research is needed for these factors. Most recent studies have shown a trend towards an overall improvement in quality of life[4]. No studies performed immediately after treatment have been able to find definitive results as they struggle to find and keep participants willing to perform an exercise intervention.

Practical adviceEdit

Exercise is beneficial in recovering from cancer treatment but, structured program shouldn't be implemented until the patient has had time to naturally recover. Research into this length of time should be considered however, conversations with you're oncologist regarding recovery is the best start to make.

Local support organisationsEdit

Further readingsEdit

ReferencesEdit

  1. a b c d e f g h i j k l Thorsen, L. et al. (2005) 'Effectiveness of physical activity on cardio-respiratory fitness and health-related quality of life in young and middle-aged cancer patients shortly after chemotherapy'. Journal of clinical oncology. 23(10):2378-88
  2. a b Burnham TR, Wilcox A. (2002) 'Effects of exercise on physiological and psychological variables in cancer survives'. Med Sci Sports Exerc. 34:1863-67
  3. a b c d Dimeo, FC. et al. (2000) 'Effects of physical activity on the fatigue and psychological status of cancer patients during chemotherapy'. Cancer. 85(10):2273-77
  4. a b c d Duijts SF. et al. (2011). 'Effectivness of behavioural techniques and physical exercise on psycholocial functioning and health-related quality of life in breast cancer patients and survivers-a meta-analysis'. Psycol-oncology. 20(2):115-126
  5. Cancer Council Australia. https://www.cancer.org.au/about-cancer/faq.html