Exercise interventions on health‐related quality of life for people with cancer during active treatment

Abstract

Background

People with cancer undergoing active treatment experience numerous disease‐ and treatment‐related adverse outcomes and poorer health‐related quality of life (HRQoL). Exercise interventions are hypothesized to alleviate these adverse outcomes. HRQoL and its domains are important measures of cancer survivorship, both during and after the end of active treatment for cancer.

Objectives

To evaluate the effectiveness of exercise on overall HRQoL outcomes and specific HRQoL domains among adults with cancer during active treatment.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed MEDLINE, EMBASE, CINAHL, PsycINFO, PEDRO, LILACS, SIGLE, SportDiscus, OTSeeker, Sociological Abstracts from inception to November 2011 with no language or date restrictions. We also searched citations through Web of Science and Scopus, PubMed's related article feature, and several websites. We reviewed reference lists of included trials and other reviews in the field.

Selection criteria

We included all randomized controlled trials (RCTs) and quasi‐randomized controlled clinical trials (CCTs) comparing exercise interventions with usual care or other type of non‐exercise comparison intervention to maintain or enhance, or both, overall HRQoL or at least one distinct domain of HRQoL. Included trials tested exercise interventions that were initiated when adults with cancer were undergoing active cancer treatment or were scheduled to initiate treatment.

Data collection and analysis

Five paired review authors independently extracted information on characteristics of included trials, data on effects of the intervention, and assessed risk of bias based on predefined criteria. Where possible, we performed meta‐analyses for HRQoL and HRQoL domains for the reported difference between baseline values and follow‐up values using standardized mean differences (SMDs) and a random‐effects model by length of follow‐up. We also reported the SMD at follow‐up between the exercise and control groups. Because investigators used many different HRQoL and HRQoL domain instruments and often more than one for the same domain, we selected the more commonly used instrument to include in the SMD meta‐analyses. We also report the mean difference for each type of instrument separately.

Main results

We included 56 trials with 4826 participants randomized to an exercise (n = 2286) or comparison (n = 1985) group. Cancer diagnoses in trial participants included breast, prostate, gynecologic, hematologic, and other. Thirty‐six trials were conducted among participants who were currently undergoing active treatment for their cancer, 10 trials were conducted among participants both during and post active cancer treatment, and the remaining 10 trials were conducted among participants scheduled for active cancer treatment. Mode of exercise intervention differed across trials and included walking by itself or in combination with cycling, resistance training, or strength training; resistance training; strength training; cycling; yoga; or Qigong. HRQoL and its domains were assessed using a wide range of measures.

The results suggest that exercise interventions compared with control interventions have a positive impact on overall HRQoL and certain HRQoL domains. Exercise interventions resulted in improvements in: HRQoL from baseline to 12 weeks' follow‐up (SMD 0.33; 95% CI 0.12 to 0.55) or when comparing difference in follow‐up scores at 12 weeks (SMD 0.47; 95% CI 0.16 to 0.79); physical functioning from baseline to 12 weeks' follow‐up (SMD 0.69; 95% CI 0.16 to 1.22) or 6 months (SMD 0.28; 95% CI 0.00 to 0.55); or when comparing differences in follow‐up scores at 12 weeks (SMD 0.28; 95% CI 0.11 to 0.45) or 6 months (SMD 0.29; 95% CI 0.07 to 0.50); role function from baseline to 12 weeks' follow‐up (SMD 0.48; 95% CI 0.07 to 0.90) or when comparing differences in follow‐up scores at 12 weeks (SMD 0.17; 95% CI 0.00 to 0.34) or 6 months (SMD 0.32; 95% CI 0.03 to 0.61); and, in social functioning at 12 weeks' follow‐up (SMD 0.54; 95% CI 0.03 to 1.05) or when comparing differences in follow‐up scores at both 12 weeks (SMD 0.16; 95% CI 0.04 to 0.27) and 6 months (SMD 0.24; 95% CI 0.03 to 0.44). Further, exercise interventions resulted in a decrease in fatigue from baseline to 12 weeks' follow‐up (SMD ‐0.38; 95% CI ‐0.57 to ‐0.18) or when comparing difference in follow‐up scores at follow‐up of 12 weeks (SMD ‐0.73; 95% CI ‐1.14 to ‐0.31). Since there is consistency of findings on both types of measures (change scores and difference in follow‐up scores) there is greater confidence in the robustness of these findings.

When examining exercise effects by subgroups, exercise interventions had significantly greater reduction in anxiety for survivors with breast cancer than those with other types of cancer. Further, there was greater reduction in depression, fatigue, and sleep disturbances, and improvement in HRQoL, emotional wellbeing (EWB), physical functioning, and role function for cancer survivors diagnosed with cancers other than breast cancer but not for breast cancer. There were also greater improvements in HRQoL and physical functioning, and reduction in anxiety, fatigue, and sleep disturbances when prescribed a moderate or vigorous versus a mild exercise program.

Results of the review need to be interpreted cautiously owing to the risk of bias. All the trials reviewed were at high risk for performance bias. In addition, the majority of trials were at high risk for detection, attrition, and selection bias.

Authors' conclusions

This systematic review indicates that exercise may have beneficial effects at varying follow‐up periods on HRQoL and certain HRQoL domains including physical functioning, role function, social functioning, and fatigue. Positive effects of exercise interventions are more pronounced with moderate‐ or vigorous‐intensity versus mild‐intensity exercise programs. The positive results must be interpreted cautiously because of the heterogeneity of exercise programs tested and measures used to assess HRQoL and HRQoL domains, and the risk of bias in many trials. Further research is required to investigate how to sustain positive effects of exercise over time and to determine essential attributes of exercise (mode, intensity, frequency, duration, timing) by cancer type and cancer treatment for optimal effects on HRQoL and its domains.

Author(s)

Shiraz I Mishra, Roberta W Scherer, Claire Snyder, Paula M Geigle, Debra R Berlanstein, Ozlem Topaloglu

Abstract

Plain language summary

Can exercise interventions enhance health‐related quality of life among people with cancer undergoing active treatment?

People with cancer undergoing treatment often have many psychological and physical adverse effects as a result of their cancer and the treatment for it. They also experience poorer quality of life because of the disease and its treatment. Some studies have suggested that exercise may be helpful in reducing negative outcomes and improving the quality of life of people with cancer who are undergoing treatment. Also, a better quality of life may predict longer life. This review looked at the effect of exercise on health‐related quality of life and areas of life that make up quality of life (e.g. tiredness, anxiety, emotional health) among people with cancer who are undergoing treatment.

The review included 56 trials with a total of 4826 participants. The results suggest that exercise may improve overall quality of life right after the exercise program is completed. Exercise may also improve the person's physical ability and the way the person can function in society. Exercise also reduced tiredness at different times during and after the exercise program. The positive effects of exercise were greater when the exercise was more intense. No effects of exercise was found in the way a person views his or her body, on the person's ability to think clearly, the person's mood, feeling of pain, and on the way the person views his or her spiritual health.

However, these findings need to be viewed with caution because this review looked at many different types of exercise programs, which varied by type of setting, length of the program, and how hard the trial participants had to exercise. Also, the investigators used a number of different ways to measure quality of life.

There is a need for more research to understand how to maintain the positive effects of exercise over a longer period of time after the exercise program is completed, and to determine which parts of the exercise program are necessary (i.e. when to start the program, type of exercise, length of the program or exercise session, how hard to exercise). It is also important to find out if one type of exercise is better for a specific cancer type than another for the maximum effect on quality of life.

Author(s)

Shiraz I Mishra, Roberta W Scherer, Claire Snyder, Paula M Geigle, Debra R Berlanstein, Ozlem Topaloglu

Reviewer's Conclusions

Authors' conclusions 

Implications for practice 

This systematic review finds that exercise interventions may have beneficial effects at varying follow‐up periods on overall HRQoL and certain HRQoL domains including physical functioning, role function, social functioning, and fatigue among cancer survivors undergoing active cancer treatment for their primary or recurrent cancer. Since there is consistency of findings on both types of measures (change scores and difference in follow‐up scores) there is greater confidence in the robustness of these findings. Positive effects of exercise interventions are more pronounced with moderate or vigorous‐intensity versus mild‐intensity exercise programs. Exercise programs could be considered as an integral component for the management of HRQoL among cancer survivors undergoing active cancer treatment.

Exercise interventions also resulted in improvements at varying follow‐up periods in prostate cancer concerns, breast cancer concerns, EWB, general health perspective, anxiety, depression, and sleep disturbances.  These findings, however, need to be interpreted cautiously as their robustness is uncertain given the fact that the positive effects were observed not on the change scores but in the difference in follow‐up scores.  These findings could be because of the different number (or type) of trials reporting results in this manner or it could be that there really is not a difference because trial authors did not account for differences in baseline values.

There were positive trends and impact of exercise interventions for body image and self‐esteem, cognitive functioning, depression based on exercise program intensity, fatigue based on exercise program intensity, general health perspective, pain, and spiritual well‐being. No conclusions can be drawn based on these trends since few trials measured these outcomes or reported on the intensity of the exercise program.

The positive results must be interpreted cautiously owing to the heterogeneity of exercise programs tested and measures used to assess HRQoL and HRQoL domains, and the risk of bias in may trials. Further, a lack of understanding about important elements of exercise programs (mode, frequency, duration of sessions and programs, and intensity) for optimal effects on HRQoL and HRQoL domains would preclude informed decision‐making in clinical settings and limit practical applicability of findings.

From a practice perspective, it would be important to understand whether certain exercise attributes have more or less optimal effects on HRQoL and HRQoL domains among survivors of certain types of cancers undergoing active treatment for their cancer. Further, it would be important to understand which mode of exercise program (e.g. strength, resistance, Tai Chi, yoga, aerobic, anaerobic) coupled with what levels of essential attributes (frequency of program, duration of program and each session) is optimal for which cancer type and cancer treatment.

Implications for research 

This systematic review and meta‐analysis of 56 trials on the effects of exercise on HRQoL and HRQoL domains for cancer survivors undergoing active treatment for their cancer provides evidence that exercise interventions may have beneficial effects at varying follow‐up periods on overall HRQoL and certain HRQoL domains, including physical functioning, role function, social functioning, and fatigue, among cancer survivor undergoing active cancer treatment for their primary or recurrent cancer. Positive effects of exercise interventions are more pronounced with moderate‐ or vigorous‐intensity versus mild‐intensity exercise programs. Further, findings of this review suggests that exercise interventions may have minimal or no effects on HRQoL domains such as body image and self‐esteem, cognitive functioning, depression based on exercise program intensity, fatigue based on exercise program intensity, general health perspective, pain, and spiritual well‐being among cancer survivors undergoing active treatment for their cancer.

Further research is required to investigate whether the effect of an exercise intervention can be maintained beyond the active intervention period, and if so, how to sustain changes in exercise behaviors and positive effects of exercise on HRQoL and HRQoL domains. Empirical evidence is also needed to determine the optimal follow‐up period from end of the intervention. To further this understanding, rigorous RCTs could include qualitative research components in trials to benefit from the contextually rich insights gained from engaging participants about their experiences in exercise interventions.

More research is needed to determine essential attributes of exercise (mode, intensity, frequency, duration, timing) by cancer type and cancer treatment for optimal effects on HRQoL and its domains.

HRQoL and HRQoL domains are important measures of cancer survivorship. However, the heterogeneous range of measures used to assess HRQoL and HRQoL domains, make comparisons of findings between trials extremely difficult. Efforts such as the Patient‐Reported Outcomes Measurement Information System (PROMIS) may help address these issues (Cella 2010; National Cancer Institute 2012).

Get full text at The Cochrane Library