Sedentary time and postmenopausal breast cancer incidence

Sarah J.O. Nomura*, Chiranjeev Dash, Vanessa B. Sheppard, Deborah Bowen, Matthew Allison, Wendy Barrington, Rowan Chlebowski, Mace Coday, Lifang Hou, Barbara Howard, Michael LaMonte, Jo Ann E. Manson, Marian L. Neuhouser, Electra Paskett, Maryam Sattari, Marcia Stefanick, Jean Wactawski-Wende, Lucile L. Adams-Campbell

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Purpose: The objective of this study was to evaluate the prospective association between sedentary time and postmenopausal breast cancer incidence, and whether associations differ by race/ethnicity, physical activity levels, and body measurements. Methods: The Women’s Health Initiative Observational Study is a prospective cohort among women ages 50–79 years at baseline (1994–1998) (analytic cohort = 70,233). Baseline questionnaire data were used to estimate time spent sitting and total sedentary time. Associations between time spent sitting and invasive breast cancer incidence overall (n = 4,115 cases through September 2015), and by hormone receptor subtypes, were investigated using Cox proportional hazards regression. Analyses were replicated stratified by race/ethnicity, body measurements, and physical activity. Results: Among women in this study, 34.5% reported ≤ 5 h/day sitting, 40.9% reported 6–9 h/day and 24.7% reported ≥ 10 h/day. Time spent sitting (≥ 10 vs. ≤5 h/day adjusted HR = 1.00, 95% CI 0.92–1.09) was not associated with breast cancer incidence, regardless of hormone receptor subtype. Associations did not differ by race/ethnicity, physical activity, or body measurements. Conclusions: Results from this study do not support an association between sedentary time and breast cancer incidence.

Original languageEnglish (US)
Pages (from-to)1405-1416
Number of pages12
JournalCancer Causes and Control
Issue number12
StatePublished - Dec 1 2017


  • Body composition
  • Breast cancer
  • Physical activity
  • Sedentary
  • Sitting time

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Fingerprint Dive into the research topics of 'Sedentary time and postmenopausal breast cancer incidence'. Together they form a unique fingerprint.

Cite this