Exercise Intervention Improves Fatigue, Other Outcomes in Cancer Patients
By Emma Hitt, PhD
Medscape Medical News
March 12, 2010 (Atlanta, Georgia) — Patients who exercised during cancer treatment experienced less fatigue, more vigor, and less emotional distress than those who were less active, according to the findings of a randomized trial evaluating an exercise intervention.
Jennifer Wenzel, PhD, RN, assistant professor at Johns Hopkins School of Nursing in Baltimore, Maryland, presented the findings here at the 16th International Conference on Cancer Nursing. The findings represent the completion of work initiated by Victoria Mock, PhD, also from Johns Hopkins, now deceased.
Of 620 eligible patients, 138 consented to be in the study; 73 were randomized to the exercise group and 65 were randomized to the usual-activity group. Patients had newly diagnosed nonmetastatic cancer and had no concurrent health problems or disabilities that limited their ability to participate. At the time of study enrollment, they were not exercising more than 3 times (or 120 minutes) per week.
The mean age of the study participants was 60.2 years. Of the patients, 55.6% had prostate cancer and 32.5% had breast cancer. Patients were to receive treatment with chemotherapy and/or external-beam radiation therapy.
Participants in the exercise group received an individualized exercise prescription on the basis of their physical condition. Patients were asked to walk briskly for 10 minutes, increasing to 30 minutes, 5 days a week. The walking intensity was designed to reach approximately 50% to 70% of maximum heart rate. The level of aerobic activity for walking, jogging, running, swimming, and biking was evaluated using the Physical Activity Questionnaire 5-activity subscale (PAQFA) and calculated in METs/hour per week.
Of participants in the exercise group, 68% adhered to their exercise prescription; of those in the usual-activity group, 12% of exercised at a level greater than that assigned to the exercise group. A total of 68 patients in the exercise group and 58 patients in the usual-activity group completed the study.
Increased aerobic exercise was significantly associated with less fatigue when measured with the Piper Fatigue Scale (P?< .001), the Symptom Distress Scale (SDS) fatigue subscale (P?< .005), and the Profile of Mood States (POMS) fatigue subscale (P < .02), after controlling for baseline outcome, age, and baseline and posttest PAQFA.
Participants who exercised throughout the study period had 7.5% more vigor on the POMS subscale (P?< .001). With respect to quality of life, those who exercised had 3% less emotional distress on both the POMS total scale and the Medical Outcomes Study Short-Form Health Survey (MOS SF-36) emotional well-being subscale, compared with those who were less active (P?= .021).
"A flexible, home-based exercise program has few risks and potential benefit that may be attainable for solid tumor patients, regardless of diagnosis," Dr. Wenzel said during the presentation. "Future intervention studies among patients receiving active cancer treatment should evaluate exercise guidelines specific to age or treatment type and, possibly, to cancer diagnosis."
According to Dr. Wenzel, interventions, including exercise, might need to be targeted to improve retention among study participants with less education and those from minority populations. "Lack of retention may prevent these already vulnerable groups from participating in an intervention that has many potential benefits," she told Medscape Oncology.
"Exercise interventions are receiving increasing attention and have been shown to have some benefit," said Mary Lou Siefert, DNSc, assistant professor at the William F. Connell School of Nursing at Boston College in Massachusetts. "I would continue to suggest to my patients that short amounts of exercise, such as walking, are helpful," she told Medscape Oncology.
According to Dr. Siefert, the findings confirm those of other studies that have been published in the breast cancer literature. "This study evaluated 2 treatment types in 2 types of cancer," she said. "However, as the authors acknowledge, we really need to look at other cancers and populations as well," she said.
The research was supported by a grant from the National Institutes of Health, the National Cancer Institute, and the National Institute of Nursing Research, with additional support provided by the Johns Hopkins University School of Nursing (JHUSON) Center for Collaborative Intervention Research. Dr. Siefert has disclosed no relevant financial relationships.
16th International Conference on Cancer Nursing (ICCN): Abstract?O-36. Presented March?8, 2010.
