Fatigue (PDQ®): Supportive care - Health Professional Information [NCI] - Intervention
Table 2. Centrally Acting Stimulants for Adult Cancer Patients continued...
Preliminary studies [35,36,37][Level of evidence: I];[Level of evidence: II];[39,40][Level of evidence: III];[41,42][Level of evidence: IV] suggest that exercise (including light- to moderate-intensity walking programs) has potential benefits for people with cancer. The benefits shown in these studies and observed in clinical settings include improved physical energy, appetite stimulation, and/or enhanced functional capacity, with improvements in quality of life and in many aspects of psychologic state (e.g., improved outlook and sense of well-being, enhanced sense of commitment, and the ability to meet the challenges of cancer and cancer treatment).
Several reviews and National Comprehensive Cancer Network guidelines outline numerous studies that support the beneficial effects of exercise on fatigue.[43,44] Reductions in fatigue of about 35% and improvements in vitality of 30% have been shown in randomized trials, with stronger effects being shown during cancer therapy in some studies and after therapy in other studies.[43,45] Many initial trials of exercise programs focused on women with breast cancer, but later studies included men with prostate cancer, multiple myeloma, and colorectal cancer. Some studies have had methodologic weaknesses, including the following:[Level of evidence: I]
- Selection biases and nonrepresentative samples.
- Recruitment of patients into randomized trials.
- Poor adherence to exercise interventions.
- Highly varied assessments of research variables and outcome measures.
- Lack of adequate control groups.
Some examples of the breadth of trials evaluating exercise are discussed in the following paragraphs. One study of patients undergoing peripheral blood stem cell transplantation found symptomatic benefits and improvements in mood in patients who participated in the interval-training program versus the control group.[48,49][Level of evidence: I] Supervised aerobic group exercise provided functional and quality-of-life benefits for women during treatment for breast cancer.[Level of evidence: I] Exercise improved function in patients treated for breast cancer.[51,52][Level of evidence: I]
In a study of 545 breast cancer survivors who were, on average, 6 months postdiagnosis, increased physical activity was consistently related to both improved physical functioning and reduced fatigue and bodily pain. Prediagnosis physical activity was associated with better physical functioning at 39 months but generally unrelated to symptoms. Increased physical activity after cancer was related to less fatigue and pain and better physical functioning. Significant positive associations were found with moderate to vigorous recreational physical activity but not household activity. This study suggests that breast cancer survivors may be able to decrease fatigue and bodily pain and be better able to pursue daily activities by increasing their recreational physical activities after cancer.[Level of evidence: II]