Past Recreational Physical Activity, Body Size, and All-Cause Mortality Following Breast Cancer Diagnosis: Results From the Breast Cancer Family Registry

Breast Cancer Res Treat. 2010 Sep;123(2):531-42. doi: 10.1007/s10549-010-0774-6. Epub 2010 Feb 7.

Abstract

Few studies have considered the joint association of body mass index (BMI) and physical activity, two modifiable factors, with all-cause mortality after breast cancer diagnosis. Women diagnosed with invasive breast cancer (n = 4,153) between 1991 and 2000 were enrolled in the Breast Cancer Family Registry through population-based sampling in Northern California, USA; Ontario, Canada; and Melbourne and Sydney, Australia. During a median follow-up of 7.8 years, 725 deaths occurred. Baseline questionnaires assessed moderate and vigorous recreational physical activity and BMI prior to diagnosis. Associations with all-cause mortality were assessed using Cox proportional hazards regression, adjusting for established prognostic factors. Compared with no physical activity, any recreational activity during the 3 years prior to diagnosis was associated with a 34% lower risk of death [hazard ratio (HR) = 0.66, 95% confidence interval (CI): 0.51-0.85] for women with estrogen receptor (ER)-positive tumors, but not those with ER-negative tumors; this association did not appear to differ by race/ethnicity or BMI. Lifetime physical activity was not associated with all-cause mortality. BMI was positively associated with all-cause mortality for women diagnosed at age > or =50 years with ER-positive tumors (compared with normal-weight women, HR for overweight = 1.39, 95% CI: 0.90-2.15; HR for obese = 1.77, 95% CI: 1.11-2.82). BMI associations did not appear to differ by race/ethnicity. Our findings suggest that physical activity and BMI exert independent effects on overall mortality after breast cancer.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Australia / epidemiology
  • Body Mass Index
  • Body Size*
  • Breast Neoplasms / diagnosis
  • Breast Neoplasms / genetics
  • Breast Neoplasms / mortality*
  • Breast Neoplasms / physiopathology
  • California / epidemiology
  • Child
  • Exercise*
  • Female
  • Genetic Predisposition to Disease
  • Humans
  • Likelihood Functions
  • Middle Aged
  • Ontario / epidemiology
  • Pedigree
  • Prognosis
  • Proportional Hazards Models
  • Receptors, Estrogen / analysis
  • Recreation*
  • Registries
  • Risk Assessment
  • Risk Factors
  • Surveys and Questionnaires
  • Time Factors
  • Young Adult

Substances

  • Receptors, Estrogen