Randomized trial of a physical activity intervention in women with metastatic breast cancer

Exercise interventions improve fitness, functional capacity, and quality of life in patients with early-stage breast cancer, but to the authors' knowledge there are few data regarding the feasibility or potential benefits of exercise in women with metastatic breast cancer.

Individuals with metastatic breast cancer were randomized 1:1 to a 16-week moderate-intensity exercise intervention or wait-list control group. Intervention goals included 150 minutes of moderate-intensity aerobic exercise per week. The baseline and 16-week evaluations included a modified Bruce Ramp treadmill test, 7-day Physical Activity Recall interview, and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ C-30) questionnaire.

A total of 101 participants were randomized (48 to the intervention group and 53 to the control group). The median age of the participants was 49 years, the median time since the diagnosis of metastatic breast cancer was 1.1 years, and approximately 42% of participants were undergoing chemotherapy at the time of enrollment. Study attrition was higher in the intervention arm (14 participants vs 8 participants; P = .15). Women randomized to the exercise intervention experienced a nonsignificant increase with regard to minutes of weekly exercise (62.4 minutes vs 46.0 minutes; P = .17) and physical functioning (EORTC QLQ C30: 4.79 vs 0.93 [P = .23] and Bruce Ramp Treadmill test: 0.61 minutes vs 0.37 minutes [P = .35]) compared with control participants.

Participation in an exercise intervention did not appear to result in significant improvements in physical functioning in a heterogeneous group of women living with advanced breast cancer. Given the significant benefits of exercise in women with early-stage breast cancer, more work is needed to explore alternative interventions to determine whether exercise could help women with metastatic disease live more fully with fewer symptoms from disease and treatment.