title: Breast cancer mortality in relation to receipt of screening mammography: a case-control study in Saskatchewan, Canada.
abstract: OBJECTIVE
  The efficacy of screening mammography in reducing breast cancer mortality continues to be controversial. In addition, few data exist on the efficacy of screening mammography in women 70 years of age or older. An organized screening mammogram program has existed in Saskatchewan since the mid-1990s. It offers mammography every 2 years to women ≥50 years of age.
  
  
  METHODS
  We conducted a population-based case-control study to evaluate the efficacy of screening mammography, as practiced in Saskatchewan, Canada. Cases (n = 501) were women who died of breast cancer during 1995-2008 and were at least 52 years of age at the time of their diagnosis. Controls (n = 5,009) were matched to cases on birth year and duration of healthcare coverage prior to the cases' breast cancer diagnosis date. In cases and controls, receipt of screening mammography during the several years up to and including the date of the case's diagnosis of breast cancer was ascertained from the records of the screening program.
  
  
  RESULTS
  Receipt of a screening mammogram in the preceding 2 years was more common among controls (53 %) than cases (37 %), OR 0.51 (95 % CI 0.42-0.62). A decreased risk was observed among women in all age groups, including those 70-79 years (OR 0.40; 95 % CI 0.27-0.60).
  
  
  CONCLUSIONS
  Our findings suggest that receipt of screening mammography among women in Saskatchewan has been associated with a decreased risk of death from breast cancer.
authors.affiliation: Department of Epidemiology, University of Washington, Box 357236, 1959 NE Pacific Street, Health Sciences F-262, Seattle, WA, 98195-7236, USA. gpocobel@uw.edu.
authors.forename: Gaia
authors.initials: G
authors.lastname: Pocobelli
authors.affiliation: Department of Epidemiology, University of Washington, Box 357236, 1959 NE Pacific Street, Health Sciences F-262, Seattle, WA, 98195-7236, USA.|Public Health Sciences, Fred Hutchinson Cancer, Box 358080, 1100 Fairview Ave N, Building M, Mailstop: M4-C308, PO Box 19024, Seattle, WA, 98109-1024, USA.
authors.forename: Noel S
authors.initials: NS
authors.lastname: Weiss
mesh_terms: D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000401:mortality*; D016022:Case-Control Studies; D055088:Early Detection of Cancer / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening; D008875:Middle Aged; D012306:Risk; D012525:Saskatchewan; D013997:Time Factors; D016896:Treatment Outcome