Exercise reduces cancer-related fatigue, boosts muscle strength among patients with breast cancer
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CHICAGO — Patients with breast cancer experienced reductions in cancer-related fatigue and improved muscle strength through an exercise regimen combining aerobic walking and resistance band training, according results of a randomized phase 2 trial presented at ASCO Annual Meeting.
"Cancer-related fatigue is among the most prevalent and noxious toxicities experienced by patients with breast cancer and survivors,” Po-Ju Lin, MD, PhD, postdoctoral research associate at the University of Rochester’s J.P. Wilmot Cancer Institute, said during the presentation. “Up to 80% of [patients with] breast cancer who receive radiation experience cancer-related fatigue, and more than 30% of breast cancer survivors continue to experience fatigue after completion of treatment. This toxicity affects patients’ ability to physically function and to perform daily activities.”
Lin and colleagues randomly assigned 89 patients with breast cancer (mean age, 55.5 years; standard deviation [SD], ±9.6; 88% white) to either a 6-week Exercise for Cancer Patients (EXCAP) program plus standard care (n = 48) or standard care only (n = 41).
EXCAP is a standardized, home-based, individually tailored exercise program consisting of daily walking and resistance band training. The walking program included a 5% to 20% weekly step increase, with steps monitored by pedometer. The resistance training involved 16 exercises, 10 of which were required, with increases from one to as many as four sets of eight to 15 repetitions.
Almost all the participants (99%) had previously undergone surgery, 51% had undergone chemotherapy and 37% had received radiation. Nearly half of the participants (47%) were receiving radiation therapy, and 46% were taking hormone therapy.
The researchers used the Brief Fatigue Inventory to evaluate cancer-related fatigue and cancer-related fatigue interference with daily activities, and they assessed upper- and lower-body strength before and after the intervention through a chest press and leg extension strength test.
T-tests were used to evaluate within-group changes, whereas analysis of covariance with pre-intervention as the covariate was used to assess between-group changes.
Three patients in the standard care group and eight patients in the EXCAP group dropped out of the study.
Results showed participants in the EXCAP intervention experienced reductions in cancer-related fatigue (–0.9 [SD, ±0.3]; P = .01) and cancer-related fatigue interference with daily activities (–1.1 [SD, ±0.3]; P < .001) from before to after the intervention. Patients in the control group showed no reductions.
Mean improvement in cancer-related fatigue and cancer-related fatigue interference with daily activities from before to after the intervention also appeared significantly higher among the EXCAP group (P < .01 for both).
Participants in the EXCAP intervention showed improvements in upper-body strength (3.9 [SD, ±1.4]; P < .01) and lower-body strength (6.4 [SD, ±1.3]; P < .01), whereas control patients did not. EXCAP participants had a significantly higher mean increase in lower body strength compared with the control group (P = .01).
“In terms of the correlation between muscular strength and cancer-related fatigue, our findings support our hypothesis that changes in lower muscular strength are significantly and negatively correlated with changes in cancer-related fatigue, suggesting that patients with breast cancer receiving radiation therapy, or survivors, have declined lower-body muscular strength and also feel more fatigue,” Lin said. “We did not see a significant correlation between upper-body muscular strength and cancer-related fatigue; however, it follows the same direction.”
Lin said additional studies will further evaluate these associations and seek to better understand their mechanisms.
“We need more phase 3 randomized controlled trials to definitively confirm the effects of exercise on cancer-related fatigue, particularly targeting patients receiving radiation therapy,” Lin said . “Future studies should compare EXCAP to behavioral placebo, controlling for specific and nonspecific components, and include an objective measure of muscular strength. Future studies should also consider collecting biological samples, such as serum samples and muscle tissue, to further understand the possible mechanism of cancer-related fatigue and study exercise genetics and epigenetics.” – by Jennifer Byrne
Reference:
Lin P, et al. Abstract 11507. Presented at: ASCO Annual Meeting; May 31-June 4, 2019; Chicago.
Disclosures: Lin reports no relevant disclosures. Please see the abstract for all other researchers’ relevant financial disclosures.