title: Benefit of screening mammography in reducing the rate of late-stage breast cancer diagnoses (United States).
abstract: OBJECTIVE
  We studied the benefit of modern mammography screening in community settings, evaluating age-related differences in rates of late-stage breast cancer detection.
  
  
  METHODS
  Our multicenter population-based case-control study included 931 black and white women with incident breast cancer (American Joint Commission on Cancer Stage IIB or higher) diagnosed 1994-1998 and 4,016 randomly sampled controls never diagnosed with breast cancer. Adjusted odds ratios (ORs) estimated the relative rate of late-stage diagnosis in screened and non-screened women.
  
  
  RESULTS
  Women aged 50-64 at diagnosis with at least one screening mammogram in the previous 2 years were significantly less likely to have late-stage diagnosis (OR = 0.41, 95% CI 0.33-0.52). Results for women aged 40-49 were consistent with a screening benefit, although the confidence interval marginally overlapped the null (OR = 0.81, 95% CI 0.64-1.02). Mammography screening was associated with lower rates of late-stage breast cancer among both premenopausal (OR = 0.64, 95% CI 0.50-0.81) and postmenopausal (OR = 0.44, 95% CI 0.35-0.56) women.
  
  
  CONCLUSIONS
  With modern mammography in the community, rates of late-stage breast cancer diagnoses are lower in screened compared to non-screened women ages 40 and older, but age-related differences persist.
authors.affiliation: Center for Clinical Epidemiology and Biostatistics and Department of Biostatistics and Epidemiology, University of Pennsylvania, 801 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA. snorman@cceb.med.upenn.edu
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Norman
authors.forename: A Russell
authors.initials: AR
authors.lastname: Localio
authors.forename: Lan
authors.initials: L
authors.lastname: Zhou
authors.forename: Anita L
authors.initials: AL
authors.lastname: Weber
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Coates
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Malone
authors.forename: Leslie
authors.initials: L
authors.lastname: Bernstein
authors.forename: Polly A
authors.initials: PA
authors.lastname: Marchbanks
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Liff
authors.forename: Nancy C
authors.initials: NC
authors.lastname: Lee
authors.forename: Marion R
authors.initials: MR
authors.lastname: Nadel
mesh_terms: D000328:Adult; D017677:Age Distribution; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D016022:Case-Control Studies; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D017698:Postmenopause; D017697:Premenopause; D012307:Risk Factors; D018426:SEER Program; D014481:United States / Q000453:epidemiology; D044465:White People