Randomized, controlled trial of resistance training in breast cancer patients receiving adjuvant radiotherapy: results on cancer-related fatigue and quality of life

Background: Exercise has been reported to decrease cancer-related fatigue and to increase quality of life (QoL) in various breast cancer (BC) populations. However, studies investigating exercise during radiotherapy or resistance training are scarce. We conducted a randomized, controlled trial (BEST study) to assess the efficacy of 12-week resistance training on fatigue beyond possible psychosocial effects of a group-based intervention.

Patients and methods: One hundred sixty patients with BC stage 0-III were randomly assigned to a 12-week progressive resistance training (2 times/week) or a 12-week relaxation control (RC, 2 times/week). Both interventions were group-based. The primary end point fatigue was assessed with a 20-item multidimensional questionnaire, QoL with EORTC questionnaires. Statistical analyses were based on analysis of covariance models for the individual changes from baseline to week 13.

Results: Adherence to the intervention program as well as the completion rate (97%) for the primary outcome variable fatigue was high. In intention-to-treat analyses for the N = 155 patients, significant between-group mean differences (MD) favoring the exercise group (EX) were observed for general fatigue (P = 0.044), especially for the subscale physical fatigue [MD = -0.8; 95% confidence interval -1.5 to -0.2, P = 0.013], but not for affective (P = 0.91) or cognitive fatigue (P = 0.65). For QoL, significantly larger improvements regarding the role function (P = 0.035) and pain (P = 0.040) were noted among exercisers compared with RCs. Future perspective improved significantly stronger in the RC group compared with the EX group (P = 0.047).

Conclusions: The 12-week resistance training program was a safe, feasible and efficacious strategy to improve cancer-related fatigue and components of QoL in BC patients during adjuvant radiotherapy. As exercise was compared with another group-based intervention, results indicate that resistance training effects on fatigue and QoL go beyond psychosocial benefits, and that the clinically relevant overall benefit of resistance exercise compared with usual care can be assumed to be higher.

Trial registration: ClinicalTrials.gov NCT01468766.