title: Prospective study of physical activity and the risk of ovarian cancer.
abstract: BACKGROUND
  Available studies on physical activity and ovarian cancer have produced inconsistent findings, with some previous studies reporting a positive association between vigorous physical activity and ovarian cancer risk.
  
  
  METHODS
  We prospectively investigated the relations of self-reported moderate and vigorous physical activity to ovarian cancer in a cohort of 96,216 US women aged 51-72 years at baseline, followed from 1996-1997 to 31 December 2003.
  
  
  RESULTS
  During seven years of follow-up, we documented 309 cases of epithelial ovarian carcinoma. In analyses adjusted for age, the relative risks (RRs) of ovarian cancer for individual and joint combinations of moderate and vigorous physical activity such as entirely inactive, neither moderate nor vigorous physical activity, moderate physical activity only, vigorous physical activity only, and both moderate and vigorous physical activity were 0.88, 1.0 (reference), 0.89, 1.05, and 1.08 (95% confidence interval (CI) = 0.81-1.43, respectively. After multivariate adjustment, the relation was essentially unchanged (RR comparing women with both moderate and vigorous physical activity to those with neither moderate nor vigorous physical activity = 1.10; 95% CI = 0.82-1.48). The null association between physical activity and ovarian cancer persisted in subgroups of women as defined by body mass index, parity, oral contraceptive use, menopausal hormone therapy, family history of ovarian cancer, and other variables (all p values for interaction >0.05).
  
  
  CONCLUSIONS
  Neither moderate nor vigorous physical activity showed a statistically significant association with ovarian cancer in this large cohort of women.
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Blvd, Rockville, MD 20892, USA. michael.leitzmann@klinik.uni-regensburg.de
authors.forename: Michael F
authors.initials: MF
authors.lastname: Leitzmann
authors.forename: Corinna
authors.initials: C
authors.lastname: Koebnick
authors.forename: Steven C
authors.initials: SC
authors.lastname: Moore
authors.forename: Kim N
authors.initials: KN
authors.lastname: Danforth
authors.forename: Louise A
authors.initials: LA
authors.lastname: Brinton
authors.forename: Albert R
authors.initials: AR
authors.lastname: Hollenbeck
authors.forename: Arthur
authors.initials: A
authors.lastname: Schatzkin
authors.forename: James V
authors.initials: JV
authors.lastname: Lacey
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors