Effects of exercise during adjuvant chemotherapy on breast cancer outcomes

• Published in: Medicine and science in sports and exercise Vol. 46; no. 9; p. 1744
• Main Authors: Courneya, Kerry S, Segal, Roanne J, McKenzie, Donald C, Dong, Huiru, Gelmon, Karen, Friedenreich, Christine M, Yasui, Yutaka, Reid, Robert D, Crawford, Jennifer J, Mackey, John R
• Format: Journal Article
• Language: English
• Published: United States 01.09.2014
• Subjects: Antineoplastic Agents - therapeutic use; Breast Neoplasms - complications; Breast Neoplasms - drug therapy; Breast Neoplasms - pathology; Bridged-Ring Compounds - therapeutic use; Chemotherapy, Adjuvant; Combined Modality Therapy - methods; Disease-Free Survival; Exercise Therapy - methods; Female; Follow-Up Studies; Humans; Middle Aged; Neoplasm Staging; Obesity - complications; Receptors, Estrogen - analysis; Resistance Training; Survival Rate; Taxoids - therapeutic use; Treatment Outcome
• DOI: 10.1249/mss.0000000000000297

Observational studies suggest that physical activity after a breast cancer diagnosis is associated with improved cancer outcomes; however, no randomized data are available. Here, we report an exploratory follow-up of cancer outcomes from the Supervised Trial of Aerobic versus Resistance Training (START). The START was a Canadian multicenter trial that randomized 242 breast cancer patients between 2003 and 2005 to usual care (n = 82), supervised aerobic (n = 78), or resistance (n = 82) exercise during chemotherapy. The primary end point for this exploratory analysis was disease-free survival (DFS). Secondary end points were overall survival, distant DFS, and recurrence-free interval. The two exercise arms were combined for analysis (n = 160), and selected subgroups were explored. After a median follow-up of 89 months, there were 25/160 (15.6%) DFS events in the exercise groups and 18/82 (22.0%) in the control group. Eight-year DFS was 82.7% for the exercise groups compared with 75.6% for the control group (HR, 0.68; 95% confidence interval (CI), 0.37-1.24; log-rank, P = 0.21). Slightly stronger effects were observed for overall survival (HR, 0.60; 95% CI, 0.27-1.33; log-rank, P = 0.21), distant DFS (HR, 0.62; 95% CI, 0.32-1.19; log-rank, P = 0.15), and recurrence-free interval (HR, 0.58; 95% CI, 0.30-1.11; Gray test, P = 0.095). Subgroup analyses suggested potentially stronger exercise effects on DFS for women who were overweight/obese (HR, 0.59; 95% CI, 0.27-1.27), had stage II/III cancer (HR, 0.61; 95% CI, 0.31-1.20), estrogen receptor-positive tumors (HR, 0.58; 95% CI, 0.26-1.29), human epidermal growth factor receptor 2-positive tumors (HR, 0.21; 95% CI, 0.04-1.02), received taxane-based chemotherapies (HR, 0.46; 95% CI, 0.19-1.15), and ≥85% of their planned chemotherapy (HR, 0.50; 95% CI, 0.25-1.01). This exploratory follow-up of the START provides the first randomized data to suggest that adding exercise to standard chemotherapy may improve breast cancer outcomes. A definitive phase III trial is warranted.