title: Subgroup effects in a randomised trial of different types and doses of exercise during breast cancer chemotherapy.
abstract: BACKGROUND
  The Combined Aerobic and Resistance Exercise Trial tested different types and doses of exercise in breast cancer patients receiving chemotherapy. Here, we explore potential moderators of the exercise training responses.
  
  
  METHODS
  Breast cancer patients initiating chemotherapy (N=301) were randomly assigned to three times a week, supervised exercise of a standard dose of 25-30 min of aerobic exercise, a higher dose of 50-60 min of aerobic exercise, or a higher dose of 50-60 min of combined aerobic and resistance exercise. Outcomes were patient-reported symptoms and health-related fitness. Moderators were baseline demographic, exercise/fitness, and cancer variables.
  
  
  RESULTS
  Body mass index moderated the effects of the exercise interventions on bodily pain (P for interaction=0.038), endocrine symptoms (P for interaction=0.029), taxane/neuropathy symptoms (P for interaction=0.013), aerobic fitness (P for interaction=0.041), muscular strength (P for interaction=0.007), and fat mass (P for interaction=0.005). In general, healthy weight patients responded better to the higher-dose exercise interventions than overweight/obese patients. Menopausal status, age, and baseline fitness moderated the effects on patient-reported symptoms. Premenopausal, younger, and fitter patients achieved greater benefits from the higher-dose exercise interventions.
  
  
  CONCLUSIONS
  Healthy weight, fitter, and premenopausal/younger breast cancer patients receiving chemotherapy are more likely to benefit from higher-dose exercise interventions.
authors.affiliation: Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB T6G 2H9, Canada.
authors.forename: K S
authors.initials: KS
authors.lastname: Courneya
authors.affiliation: School of Kinesiology, University of British Columbia, Victoria, BC V6T 1Z1, Canada.
authors.forename: D C
authors.initials: DC
authors.lastname: McKenzie
authors.affiliation: 1] Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada [2] Cross Cancer Institute, Edmonton, AB T6G 1Z2, Canada.
authors.forename: J R
authors.initials: JR
authors.lastname: Mackey
authors.affiliation: 1] Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada [2] Department of Medical Oncology, British Columbia Cancer Agency, Vancouver, BC V5Z 4E6, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Gelmon
authors.affiliation: Department of Cancer Epidemiology and Prevention Research, Alberta Health Services, Calgary, AB T2S 3C3, Canada.
authors.forename: C M
authors.initials: CM
authors.lastname: Friedenreich
authors.affiliation: School of Public Health, University of Alberta, Edmonton, AB T6G 1C9, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Yasui
authors.affiliation: Division of Prevention and Rehabilitation, University of Ottawa Heart Institute, Ottawa, ON K1Y 4W7, Canada.
authors.forename: R D
authors.initials: RD
authors.lastname: Reid
authors.affiliation: Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB T6G 2H9, Canada.
authors.forename: J R
authors.initials: JR
authors.lastname: Vallerand
authors.affiliation: Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB T6G 2H9, Canada.
authors.forename: S C
authors.initials: SC
authors.lastname: Adams
authors.affiliation: Department of Medical Oncology, The Ottawa Hospital Cancer Center, Ottawa, ON K1H 8L8, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Proulx
authors.affiliation: School of Kinesiology, University of British Columbia, Victoria, BC V6T 1Z1, Canada.
authors.forename: L B
authors.initials: LB
authors.lastname: Dolan
authors.affiliation: 1] Department of Medical Oncology, The Ottawa Hospital Cancer Center, Ottawa, ON K1H 8L8, Canada [2] Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Wooding
authors.affiliation: 1] Department of Medical Oncology, The Ottawa Hospital Cancer Center, Ottawa, ON K1H 8L8, Canada [2] Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada.
authors.forename: R J
authors.initials: RJ
authors.lastname: Segal
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000534:rehabilitation*; D017024:Chemotherapy, Adjuvant; D005081:Exercise Therapy / Q000145:classification / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D010349:Patient Compliance; D011379:Prognosis; D011788:Quality of Life