title: Cardiopulmonary function and age-related decline across the breast cancer survivorship continuum.
abstract: OBJECTIVE
  To evaluate cardiopulmonary function (as measured by peak oxygen consumption [VO(2peak)]) across the breast cancer continuum and its prognostic significance in women with metastatic disease.
  
  
  METHODS
  Patients with breast cancer representing four cross-sectional cohorts--that is, (1) before, (2) during, and (3) after adjuvant therapy for nonmetastatic disease, and (4) during therapy in metastatic disease--were studied. A cardiopulmonary exercise test (CPET) with expired gas analysis was used to assess VO(2peak). A Cox proportional hazards model was used to estimate the risk of death according to VO(2peak) category (< 15.4 v ≥ 15.4 mL · kg(-1) · min(-1)) with adjustment for clinical factors.
  
  
  RESULTS
  A total of 248 women (age, 55 ± 8 years) completed a CPET. Mean VO(2peak) was 17.8 ± a standard deviation of 4.3 mL · kg(-1) · min(-1), the equivalent of 27% ± 17% below age-matched healthy sedentary women. For the entire cohort, 32% had a VO(2peak) less than 15.4 mL · kg(-1) · min(-1)--the VO(2peak) required for functional independence. VO(2peak) was significantly different across breast cancer cohorts for relative (mL · kg(-1) · min(-1)) and absolute (L · min(-1)) VO(2peak) (P = .017 and P < .001, respectively); VO(2peak) was lowest in women with metastatic disease. In patients with metastatic disease (n = 52), compared with patients achieving a VO(2peak) ≤ 1.09 L · min(-1), the adjusted hazard ratio for death was 0.32 (95% CI, 0.16 to 0.67, P = .002) for a VO(2peak) more than 1.09 L · min(-1).
  
  
  CONCLUSIONS
  Patients with breast cancer have marked impairment in VO(2peak) across the entire survivorship continuum. VO(2peak) may be an independent predictor of survival in metastatic disease.
authors.affiliation: Duke University Medical Center, Durham, NC, USA. lee.w.jones@duke.edu
authors.forename: Lee W
authors.initials: LW
authors.lastname: Jones
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.forename: John R
authors.initials: JR
authors.lastname: Mackey
authors.forename: Hyman B
authors.initials: HB
authors.lastname: Muss
authors.forename: Edith N
authors.initials: EN
authors.lastname: Pituskin
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Scott
authors.forename: Whitney E
authors.initials: WE
authors.lastname: Hornsby
authors.forename: April D
authors.initials: AD
authors.lastname: Coan
authors.forename: James E
authors.initials: JE
authors.lastname: Herndon
authors.forename: Pamela S
authors.initials: PS
authors.lastname: Douglas
authors.forename: Mark
authors.initials: M
authors.lastname: Haykowsky
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000503:physiopathology; D010101:Oxygen Consumption; D011379:Prognosis