title: Physical activity and survival in postmenopausal women with breast cancer: results from the women's health initiative.
abstract: Although studies have shown that physically active breast cancer survivors have lower all-cause mortality, the association between change in physical activity from before to after diagnosis and mortality is not clear. We examined associations among pre- and postdiagnosis physical activity, change in pre- to postdiagnosis physical activity, and all-cause and breast cancer-specific mortality in postmenopausal women. A longitudinal study of 4,643 women diagnosed with invasive breast cancer after entry into the Women's Health Initiative study of postmenopausal women. Physical activity from recreation and walking was determined at baseline (prediagnosis) and after diagnosis (assessed at the 3 or 6 years post-baseline visit). Women participating in 9 MET-h/wk or more (∼ 3 h/wk of fast walking) of physical activity before diagnosis had a lower all-cause mortality (HR = 0.61; 95% CI, 0.44-0.87; P = 0.01) compared with inactive women in multivariable adjusted analyses. Women participating in ≥ 9 or more MET-h/wk of physical activity after diagnosis had lower breast cancer mortality (HR = 0.61; 95% CI, 0.35-0.99; P = 0.049) and lower all-cause mortality (HR = 0.54; 95% CI, 0.38-0.79; P < 0.01). Women who increased or maintained physical activity of 9 or more MET-h/wk after diagnosis had lower all-cause mortality (HR = 0.67; 95% CI, 0.46-0.96) even if they were inactive before diagnosis. High levels of physical activity may improve survival in postmenopausal women with breast cancer, even among those reporting low physical activity prior to diagnosis. Women diagnosed with breast cancer should be encouraged to initiate and maintain a program of physical activity.
authors.affiliation: Division of Chronic Disease Epidemiology, Yale School of Public Health, PO Box 208034, New Haven, CT 06520-8034, USA. melinda.irwin@yale.edu
authors.forename: Melinda L
authors.initials: ML
authors.lastname: Irwin
authors.forename: Anne
authors.initials: A
authors.lastname: McTiernan
authors.forename: JoAnn E
authors.initials: JE
authors.lastname: Manson
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Thomson
authors.forename: Barbara
authors.initials: B
authors.lastname: Sternfeld
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Lynette
authors.initials: L
authors.lastname: Craft
authors.forename: Dorothy
authors.initials: D
authors.lastname: Lane
authors.forename: Lisa W
authors.initials: LW
authors.lastname: Martin
authors.forename: Rowan
authors.initials: R
authors.lastname: Chlebowski
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality*; D015444:Exercise; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000517:prevention & control; D017698:Postmenopause