Background: Among breast cancer populations, exercise interventions resulted in positive but relatively small improvements on fatigue, which may be due to insensitive measures of global fatigue. Perceived fatigability-whole-body tiredness anchored to standardized tasks/activities of a specific intensity and duration-may help to detect effective exercise interventions reducing fatigue in oncology. We examined whether perceived physical fatigability improved after an exercise intervention.
Methods: This single center randomized clinical trial of 49 breast cancer survivors was conducted from 2015 to 2017, among which 41 participants (22 = exercise, 19 = control) completed the trial and reported their perceived physical fatigability at the first (Visit 1) and the last visit (Visit 3) over 6-14 weeks. Perceived physical fatigability was measured using the 10-item, self-administered Pittsburgh Fatigability Scale (PFS) scored 0-50. The mean differences of perceived physical fatigability between Visit 3 and Visit 1 were computed and compared by intervention groups using two sample t test.
Results: Among the 41 women in the study (mean age 54.9 ± 9.8 years; 80% white), sociodemographic, clinical characteristics and baseline fatigue level were similar by intervention groups, except for antiestrogen use. Post-intervention changes (mean ∆ ± SE) of PFS Physical scores were greater in the exercise group (- 4.4 ± 1.4; - 22.5%) than the control group (0.2 ± 1.4; + 1.0%) (p = .022).
Conclusion: The PFS captured a reduction in fatigue after the exercise intervention among breast cancer survivors. These findings aid mounting efforts to reduce fatigue in oncology by introducing a more sensitive instrument to measure perceived physical fatigability to better evaluate patient-reported outcomes in future cancer trials.
Trial registration: Clinicaltrials.gov identifier: NCT02770781.
Keywords: Aging; Cancer survivorship; Fatigue; Physical activity.
© 2021. The Japanese Breast Cancer Society.