title: Effects of exercise training on antitumor efficacy of doxorubicin in MDA-MB-231 breast cancer xenografts.
abstract: OBJECTIVE
  Exercise is becoming readily accepted as a beneficial adjunct therapy to maintain or enhance quality of life in breast cancer patients undergoing adjuvant chemotherapy. An essential precursor to these studies is to investigate whether exercise modulates the antitumor efficacy of chemotherapeutic agents.
  
  
  METHODS
  Athymic female mice were transplanted with MDA-MB-231 breast xenografts and randomly assigned to one of four groups (n = 21 per group): (a) control, (b) exercise-only, (c) doxorubicin-only, or (d) exercise + doxorubicin. Exercise groups performed progressive treadmill running up to 18 m/min at 0% grade for 45 minutes, 5 d/wk for 8 weeks.
  
  
  RESULTS
  Tumor growth delay was significantly longer in the doxorubicin-only and exercise + doxorubicin groups compared with the control (median 42 versus 25 days, P = 0.0082; 36 versus 25 days, P = 0.029, respectively) and exercise-only groups (median 42 versus 25 days, P = 0.029; 36 versus 25 days, P = 0.080, respectively). There was no significant difference between the doxorubicin-only and exercise + doxorubicin groups (median 42 versus 36 days, P = 0.33), suggesting that moderate intensity exercise does not significantly influence doxorubicin-induced tumor growth delay.
  
  
  CONCLUSIONS
  These studies are essential to fully understand the safety and application of exercise as a supportive intervention in cancer control.
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27705, USA. lee.w.jones@duke.edu
authors.forename: Lee W
authors.initials: LW
authors.lastname: Jones
authors.forename: Neil D
authors.initials: ND
authors.lastname: Eves
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.forename: Brian K
authors.initials: BK
authors.lastname: Chiu
authors.forename: Vickie E
authors.initials: VE
authors.lastname: Baracos
authors.forename: John
authors.initials: J
authors.lastname: Hanson
authors.forename: Lorelei
authors.initials: L
authors.lastname: Johnson
authors.forename: John R
authors.initials: JR
authors.lastname: Mackey
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000628:therapy*; D051379:Mice; D008819:Mice, Nude; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011897:Random Allocation; D016019:Survival Analysis; D013997:Time Factors; D023041:Xenograft Model Antitumor Assays / Q000379:methods
chemical_list: D000903:Antibiotics, Antineoplastic; D004317:Doxorubicin