Although current ASCO guidelines recommend exercise for patients with breast cancer during adjuvant therapy with curative intent, the guidelines state that more study is needed regarding the effects of exercise for patients with metastatic breast cancer. The results of the PREFERABLE-EFFECT trial may change that.¹

PREFERABLE-EFFECT, a randomized, prospective trial conducted in five European countries plus Australia, showed that participating in a supervised, moderate- and high-intensity exercise program for 9 months had a positive effect on cancer-related fatigue and quality of life in patients with metastatic breast cancer. Not only did an exercise program improve physical fitness, physical function, and social function in this trial, but also patients experienced reductions in symptoms of pain and dyspnea.

“It is reassuring that exercise does not worsen these symptoms of metastatic breast cancer. We had good adherence, and patients expressed gratitude for how much better they felt,” said lead author Anne May, PhD, of Utrecht Medical Center, the Julius Center, the Netherlands.” I think supervised exercise should be prescribed for patients with breast cancer, including those undergoing palliative care for metastatic disease. Even if their lifespan is limited, quality of life will be better.”

Previous studies have shown that exercise benefits quality of life and energy levels for people with less-advanced breast cancer, including health-related quality of life and fatigue. “However, whether these benefits extend to patients with metastatic disease had not been rigorously tested. And patients with metastatic disease may need a longer exercise program because they are on continuous treatment,” she said.

Study Details

The PREFERABLE-EFFECT study enrolled 357 patients with metastatic breast cancer. All participants received a physical activity tracker and generic exercise advice. Those randomly assigned to the exercise group participated in supervised hourly sessions twice a week for 9 months focused on balance, resistance training, and aerobic capacity. During the final 3 months of the study, one supervised session was replaced by unsupervised exercise and an exercise app could be used for one of the two hourly sessions per week. The control group did no supervised exercise.

At baseline, median patient age was around 55 years; 99.4% were women; about two-thirds had bone metastases; about 75% were receiving first- or second-line cancer therapy; and more than 50% were on endocrine therapy. At baseline, 58% of patients reported pain, and 57% reported dyspnea as symptoms of the disease and/or treatment.

Participants were surveyed using the European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire (EORTC QLQ-30) after 3, 6, and 9 months, assessing physical, mental, and emotional quality of life. The EORTC QLQ-FA12 questionnaire was used to assess cancer-related fatigue among participants. Scoring was from 0 to 100, with higher scores on the EORTC QLQ-30 indicating improved quality of life and higher scores on the EORTC QLQ-FA12 indicating higher levels of fatigue. Physical fitness was evaluated using the steep ramp test, which entails riding a stationary bike with increasing resistance levels until voluntary exhaustion.

Key Results

Patients assigned to the exercise program reported significantly higher scores on the EORTC QLQ-30 summary score compared with the control arm at 3, 6, and 9 months, reflecting improved quality of life. Scores were 3.9, 4.8, and 4.2 points higher than for the control arm, respectively. Also, EORTC QLQ-FA12 scores were 3.4, 5.3, and 5.6 points lower for the exercise group than for the control arm, signifying decreased fatigue at 3, 6, and 9 months, respectively.

“At our primary endpoint (6 months postbaseline) and all other timepoints, all scores were statistically significantly improved, except for fatigue at 3 months,” Dr. May said. At 6 months, participants in the exercise intervention reported improved scores on subscales of the EORTC QLQ-30, including a 5.5-point increase in social functioning, a 7.1-point decrease in pain, and a 7.6-point decrease in dyspnea. In the steep ramp test for physical fitness, participants in the exercise arm achieved an average maximum resistance that was 24.3 Watts (13%) higher than that achieved by participants in the control group.

Patients in the exercise intervention group had a 77% adherence rate, which Dr. May considered fairly high given that half of the remaining 23% died during the course of the study. “We think a 9-month supervised exercise program helps patients incorporate exercise into their routine. Many patients continued exercising beyond 9 months, and exercise became part of their daily lives and cancer treatment regimens,” she added.

According to Dr. May, physicians and nurses should recommend supervised exercise programs to patients with metastatic breast cancer as part of cancer treatment, and it should be part of insurance coverage. 

DISCLOSURE: Dr. May reported no conflicts of interest.

REFERENCE

1. May A, Hiensch A, Depenbusch J, et al: Effects of a structured and individualized exercise program on fatigue and health-related quality of life in patients with metastatic breast cancer: The multinational randomized controlled PREFERABLE-EFFECT study. 2023 San Antonio Breast Cancer Symposium. Abstract GS02-10. Presented December 7, 2023.