Exercise May Improve QOL in Metastatic Breast Cancer

The PREFERABLE-EFFECT study found that supervised resistance and aerobic exercise were associated with reduced fatigue in patients with metastatic breast cancer.

Investigators found that exercise was associated with an improvement in quality of life (QOL) and well-being for patients with metastatic breast cancer, according to findings from the PREFERABLE-EFFECT trial (NCT04120298) published in Nature Medicine.¹

There was a statistically significant reduction in physical fatigue at 6 months (between-group difference [BGD], –5.3; 95% CI, –10.0 to –0.6; adjusted P = .027) in patients with metastatic breast cancer undergoing an exercise regimen vs those who did not. An improvement in health-related QOL at 3 months (HRQOL; BGD, 3.9; 95% CI, 1.5-6.3) and at 9 months (BGD, 4.3; 95% CI, 1.4-7.3).

Of note, the 2 serious adverse events (SAEs) that occurred–– a wrist fracture and sacral stress fracture–– were unrelated to bone metastases, instead occurring as a result of exercise; exercise was continued after interruption and/or modification to the program.

“Although there is substantial evidence for the beneficial effects of exercise for people with early-stage cancer, we have seen very little research on exercise in patients with more advanced disease,” Yvonne Wengström, OCN, PhD, professor at the Department of Neurobiology, Care Sciences and Society at Karolinska Institute, said in a news release on the study findings.²

Investigators enrolled 357 patients across 8 European and Australian centers with metastatic breast cancer and a life expectancy greater than 6 months without unstable bone metastases in the study. Patients were randomly assigned 1:1 to usual care (n = 179) or a 9-month supervised exercise program (n = 178), which was individualized for each patient.

The mean age was 55.4 years old between both groups, 99.4% were female, 74.8% were receiving first- or second-line treatment, and 67.2% had bone metastases. Fatigue was reported in 49.9% of patients at baseline which was above the threshold for clinical importance. Additionally, 56.0% reported pain, and 57.4% reported dyspnea.

The exercise program consisted of 1 hour of supervised, multimodal exercise sessions twice weekly for the first 6 months. For the remaining 3 months, 1 of the sessions was made unsupervised, with no other alterations to the program. Qualified exercise professionals supervised patients in-person or via Zoom during the COVID-19 pandemic; patients conducted exercise sessions in the community- or hospital-based fitness centers or physical therapy practices close to their home address.

The exercise program consisted of resistance, aerobic, and balance exercises, with increases in intensity made gradually and adjustments made based on the health status of the patient. Individualized 12-repetition maximum strength testing was performed for all patients except those with bone metastases. The aerobic intensity was tailored to fitness levels assessed through peak power output with the steep ramp test and maximal short exercise capacity.

Patients were additionally encouraged to participate in daily physical activity for at least 30 minutes a day, with the use of a Fitbit Inspire HR as an activity tracker and an exercise app supporting the initiative. The app included all learned exercises, including ones performed at home or during unsupervised sessions.

The usual care group received written information on current physical activity and were advised to be as physically active as their health status allowed, but did not receive a structured exercise regimen. They, similarly, received a Fitbit Inspire HR to track their activity.

Patients visited the study center at baseline, as well as 3- and 6-months following baseline. Patient reported outcomes were recorded through online questionnaires at all visits and 9 months after baseline, excluding those undergoing intravenous chemotherapy; questionnaires were provided 3 days after chemotherapy treatment. EORTC QLQ-C30 and EORTC QTQ-FA12 were used to assess patient reported outcomes.

The QLQ-C30 includes a global HRQOL score, 5 functional scales, 3 symptom scales, and 6 single-item scales; the QLQ-FA12 assesses fatigue physically, emotionally, cognitively, and total fatigue.

The study primary end points include HRQOL and cancer-related physical fatigue, assessed through the patient reported outcome questionnaires at the fully supervised intervention period of 6 months.

Common AEs requiring exercise program alterations included pain (51.3%), dizziness (12.5%), muscle soreness/cramps (11.3%), and fatigue (8.9%).

References

1. Hiensch AE, Depenbusch J, Schmidt ME, et al. Supervised, structured and individualized exercise in metastatic breast cancer: a randomized controlled trial. Nat Med. Published online July 25, 2024. Accessed August 21, 2024. doi:10.1038/s41591-024-03143-y
2. Exercise program improves quality of life for metastatic breast cancer patients. News release. Karolinska Institute. August 20, 2024. Accessed August 21, 2024. https://tinyurl.com/27vuf9vm