Effect of low-intensity physical activity and moderate- to high-intensity physical exercise during adjuvant chemotherapy on physical fitness, fatigue and chemotherapy completion rates: Results of the PACES randomized clinical trial

Purpose: We evaluated the effectiveness of a low-intensity, home-based physical activity program (Onco-Move) and a moderate- to high-intensity, combined supervised resistance and aerobic exercise program (OnTrack) versus usual care (UC) in maintaining or enhancing physical fitness, minimizing fatigue, enhancing health-related quality of life, and optimizing chemotherapy completion rates in patients undergoing adjuvant chemotherapy for breast cancer.

Patients and Methods: We randomly assigned patients who were scheduled to undergo adjuvant chemotherapy (N = 230) to Onco-Move, OnTrack, or UC. Performance-based and self-reported outcomes were assessed before random assignment, at the end of chemotherapy, and at the 6-month follow-up. We used generalized estimating equations to compare the groups over time.

Results: Onco-Move and OnTrack resulted in less decline in cardiorespiratory fitness (P < .001), better physical functioning (P ≤ .001), less nausea and vomiting (P = .029 and .031, respectively) and less pain (P = .003 and .011, respectively) compared with UC. OnTrack also resulted in better outcomes for muscle strength (P = .002) and physical fatigue (P < .001). At the 6-month follow-up, most outcomes returned to baseline levels for all three groups. A smaller percentage of participants in OnTrack required chemotherapy dose adjustments than those in the UC or Onco-Move groups (P = .002). Both intervention groups returned earlier (P = .012), as well as for more hours per week (P = .014), to work than the control group.

Conclusion: A supervised, moderate- to high-intensity, combined resistance and aerobic exercise program is most effective for patients with breast cancer undergoing adjuvant chemotherapy. A home-based, low-intensity physical activity program represents a viable alternative for women who are unable or unwilling to follow the higher intensity program.