title: Pre- and postdiagnosis physical activity, television viewing, and mortality among patients with colorectal cancer in the National Institutes of Health-AARP Diet and Health Study.
abstract: OBJECTIVE
  Physical inactivity has been associated with higher mortality risk among survivors of colorectal cancer (CRC), but the independent effects of pre- versus postdiagnosis activity are unclear, and the association between watching television (TV) and mortality in survivors of CRC is previously undefined.
  
  
  METHODS
  We analyzed the associations between prediagnosis (n = 3,797) and postdiagnosis (n = 1,759) leisure time physical activity (LTPA) and TV watching and overall and disease-specific mortality among patients with CRC. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% CIs, adjusting for known mortality risk factors.
  
  
  RESULTS
  Comparing survivors of CRC reporting more than 7 hours per week (h/wk) of prediagnosis LTPA with those reporting no LTPA, we found a 20% lower risk of all-cause mortality (HR, 0.80; 95% CI, 0.68 to 0.95; P for trend = .021). Postdiagnosis LTPA of ≥ 7 h/wk, compared with none, was associated with a 31% lower all-cause mortality risk (HR, 0.69; 95% CI, 0.49 to 0.98; P for trend = .006), independent of prediagnosis activity. Compared with 0 to 2 TV hours per day (h/d) before diagnosis, those reporting ≥ 5 h/d of TV before diagnosis had a 22% increased all-cause mortality risk (HR, 1.22; 95% CI, 1.06 to 1.41; P trend = .002), and more postdiagnosis TV watching was associated with a nonsignificant 25% increase in all-cause mortality risk (HR, 1.25; 95% CI, 0.93 to 1.67; P for trend = .126).
  
  
  CONCLUSIONS
  LTPA was inversely associated with all-cause mortality, whereas more TV watching was associated with increased mortality risk. For both LTPA and TV watching, postdiagnosis measures independently explained the association with mortality. Clinicians should promote both minimizing TV time and increasing physical activity for longevity among survivors of CRC, regardless of previous behaviors.
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO. Aremhe2@mail.nih.gov.
authors.forename: Hannah
authors.initials: H
authors.lastname: Arem
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Pfeiffer
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Engels
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Alfano
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO.
authors.forename: Albert
authors.initials: A
authors.lastname: Hollenbeck
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO.
authors.forename: Yikyung
authors.initials: Y
authors.lastname: Park
authors.affiliation: Hannah Arem, Ruth M. Pfeiffer, Eric A. Engels, Catherine M. Alfano, and Charles E. Matthews, National Cancer Institute, Bethesda, MD; Albert Hollenbeck, AARP, Washington, DC; and Yikyung Park, Washington University School of Medicine, St Louis, MO.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Matthews
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000401:mortality*; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009068:Movement; D016017:Odds Ratio; D005082:Physical Exertion; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D057185:Sedentary Behavior; D013690:Television; D014481:United States / Q000453:epidemiology