title: Body mass index, physical activity, and survival after endometrial cancer diagnosis: results from the Women's Health Initiative.
abstract: OBJECTIVE
  While low physical activity and high body mass index (BMI) have been associated with higher endometrial cancer incidence, no previous studies have evaluated the association between physical activity and survival after endometrial cancer diagnosis, and studies on BMI and survival have not been performed in a prospective cohort.
  
  
  METHODS
  We examined pre-diagnosis BMI and moderate- to vigorous-intensity physical activity in relation to overall and disease-specific survival among 983 postmenopausal women who were diagnosed with endometrial cancer in the Women's Health Initiative Observational Study and Clinical Trials.
  
  
  RESULTS
  Over a median 5.2 (max 14.1) years from diagnosis to death or end of follow-up, 163 total deaths were observed, 66 of which were due to endometrial cancer. We observed a higher all-cause mortality hazard ratio (HR) = 1.85 (95% CI 1.19-2.88) comparing women with a BMI ≥ 35 kg/m(2) to women with BMI< 25 kg/m(2). For endometrial cancer-specific mortality the HR = 2.23 (95% CI 1.09-4.54) comparing extreme BMI categories. To examine histologic subtypes we analyzed type I endometrial tumors separately and found an HR = 1.20 (95% CI 1.07-1.35) associated with all-cause mortality for each 5-unit change in BMI. Moderate- to vigorous-intensity physical activity was not associated with all-cause or endometrial cancer-specific mortality.
  
  
  CONCLUSIONS
  Pre-diagnosis BMI, but not physical activity, was associated with survival among women with endometrial cancer. Future studies should investigate mechanisms and timing of BMI onset to better understand the burden of disease attributable to BMI.
authors.affiliation: Yale School of Public Health, Department of Chronic Disease Epidemiology, 60 College St., New Haven, CT 06520, USA. Hannah.arem@yale.edu
authors.forename: Hannah
authors.initials: H
authors.lastname: Arem
authors.forename: Rowan
authors.initials: R
authors.lastname: Chlebowski
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.forename: Garnet
authors.initials: G
authors.lastname: Anderson
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Stacy
authors.initials: S
authors.lastname: Sims
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Gunter
authors.forename: Melinda L
authors.initials: ML
authors.lastname: Irwin
mesh_terms: D015992:Body Mass Index; D016889:Endometrial Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D011379:Prognosis; D015996:Survival Rate; D014481:United States / Q000453:epidemiology; D016387:Women's Health