title: Recreational physical activity and breast cancer risk among women under age 45 years.
abstract: To evaluate whether recreational physical activity is associated with breast cancer among young women, the authors analyzed data from a population-based case-control study. Cases (n = 1,668) were women under age 45 years who had been newly diagnosed with breast cancer between 1990 and 1992 in Atlanta, Georgia, central New Jersey, or Seattle, Washington. Controls (n = 1,505) were frequency-matched to cases by 5-year age group and geographic area of residence. Breast cancer was not associated with recreational activity in any of the three time periods assessed (highest quartile of activity vs. lowest: age- and center-adjusted odds ratio (OR) = 0.94 (95% confidence interval (CI) 0.77-1.15) at ages 12-13 years, OR = 1.08 (95% CI 0.88-1.32) at age 20 years, and OR = 1.18 (95% CI 0.97-1.44) during the past year), with the average of the three time periods (OR = 1.02, 95% CI 0.84-1.25), or with daily climbing of at least two flights of stairs (without stopping) during the past year (daily climbing vs. never climbing: OR = 1.03, 95% CI 0.86-1.23). Estimates were not modified or confounded by body mass index, menopausal status, or caloric intake during the past year. These results do not support a protective role for physical activity in the risk of breast cancer among young women.
authors.affiliation: Division of Epidemiology, Columbia School of Public Health, New York, NY, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Gammon
authors.forename: J B
authors.initials: JB
authors.lastname: Schoenberg
authors.forename: J A
authors.initials: JA
authors.lastname: Britton
authors.forename: J L
authors.initials: JL
authors.lastname: Kelsey
authors.forename: R J
authors.initials: RJ
authors.lastname: Coates
authors.forename: D
authors.initials: D
authors.lastname: Brogan
authors.forename: N
authors.initials: N
authors.lastname: Potischman
authors.forename: C A
authors.initials: CA
authors.lastname: Swanson
authors.forename: J R
authors.initials: JR
authors.lastname: Daling
authors.forename: J L
authors.initials: JL
authors.lastname: Stanford
authors.forename: L A
authors.initials: LA
authors.lastname: Brinton
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D005845:Georgia / Q000453:epidemiology; D006801:Humans; D008593:Menopause / Q000502:physiology; D008875:Middle Aged; D009515:New Jersey / Q000453:epidemiology; D016017:Odds Ratio; D011998:Recreation; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014861:Washington / Q000453:epidemiology