title: The impact of breast cancer screening among younger women in the Barretos Region, Brazil.
abstract: OBJECTIVE
  To verify the impact of breast cancer screening in women aged 40-49 years in one region of Brazil.
  
  
  METHODS
  This is a cross-sectional study, targeted to asymptomatic women aged 40-69 years who had breast cancer screening mammography performed between January 2003 and December 2007. Logistic regression was used to estimate the risk of breast cancer by age groups (40-49, 50-59, 60-69 years).
  
  
  RESULTS
  Of the 27,133 screened women, 51.9% (14,082) were aged between 40-49 years. The odds ratio (OR) of breast cancer among the 45-49 year age cohort was not significantly different from that of 60 to 69-year-old women (OR=0.64; 95% Confidence Interval 0.39 to 1.03).
  
  
  CONCLUSIONS
  The risk of breast cancer among women aged 45 to 49 years is equivalent to that of women aged 60 to 69 years, indicating that breast cancer screening in this region of Brazil should start at the age of 45 years or immediately thereafter.
authors.affiliation: Department of Cancer Prevention, Barretos Cancer Hospital, Barretos/SP, Brazil. jacosaraiva@gmail.com
authors.forename: Jacó Saraiva
authors.initials: JS
authors.lastname: De Castro Mattos
authors.forename: Edmundo Carvalho
authors.initials: EC
authors.lastname: Mauad
authors.forename: Kari
authors.initials: K
authors.lastname: Syrjänen
authors.forename: Adhemar
authors.initials: A
authors.lastname: Longatto-Filho
authors.forename: Raphael Luiz
authors.initials: RL
authors.lastname: Haikel
authors.forename: René Aloísio
authors.initials: RA
authors.lastname: Da Costa Vieira
authors.forename: Thiago Buosi
authors.initials: TB
authors.lastname: Silva
authors.forename: Nestor
authors.initials: N
authors.lastname: De Barros
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001938:Brazil; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000517:prevention & control; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008327:Mammography; D008403:Mass Screening; D008875:Middle Aged; D016017:Odds Ratio; D012306:Risk
keywords: Breast cancer; age groups; risk; screening; younger women