title: Effects of exercise during adjuvant chemotherapy on breast cancer outcomes.
abstract: 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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: 1Faculty of Physical Education, University of Alberta, Edmonton, Alberta, CANADA; 2Ottawa Hospital Regional Cancer Center, Ottawa, Ontario, CANADA; 3School of Kinesiology, University of British Columbia, Vancouver, British Columbia, CANADA; 4British Columbia Cancer Agency, Vancouver, British Columbia, CANADA; 5Department of Cancer Epidemiology and Prevention Research, Alberta Health Services, Calgary, Alberta, CANADA; 6University of Ottawa Heart Institute, Ottawa, Ontario, CANADA; and 7Cross Cancer Institute, Edmonton, Alberta, CANADA.
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.forename: Roanne J
authors.initials: RJ
authors.lastname: Segal
authors.forename: Donald C
authors.initials: DC
authors.lastname: McKenzie
authors.forename: Huiru
authors.initials: H
authors.lastname: Dong
authors.forename: Karen
authors.initials: K
authors.lastname: Gelmon
authors.forename: Christine M
authors.initials: CM
authors.lastname: Friedenreich
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yasui
authors.forename: Robert D
authors.initials: RD
authors.lastname: Reid
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Crawford
authors.forename: John R
authors.initials: JR
authors.lastname: Mackey
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D001952:Bridged-Ring Compounds / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy / Q000379:methods; D018572:Disease-Free Survival; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D009765:Obesity / Q000150:complications; D011960:Receptors, Estrogen / Q000032:analysis; D055070:Resistance Training; D015996:Survival Rate; D043823:Taxoids / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001952:Bridged-Ring Compounds; D011960:Receptors, Estrogen; D043823:Taxoids; C080625:taxane