title: Prognosis of screen-detected breast cancers: results of a population based study.
abstract: BACKGROUND
  The reduced mortality rate from breast carcinoma among women offered screening mammography is demonstrated after 15-20 years of follow-up. However, the assessment of 5-year overall and event-free survival could represent an earlier measure of the efficacy of mammography screening program (MSP).
  
  
  METHODS
  All cases of breast cancer diagnosed in the Province of Modena between years 1996 and 2000 in women aged 50 to 69 years, were identified through the Modena Cancer Registry (MCR). Stage of disease and treatment information were obtained from clinical records. All the events occurring up to June 30, 2003 were retrieved by experienced monitors. Five-year overall and event-free survival were the principal end-points of the study.
  
  
  RESULTS
  During a 5-year period, 587 primary breast cancers were detected by the MSP and 471 primary breast cancers were diagnosed out of the MSP. The screen-detected breast cancers were smaller, more likely node negative, with low histological grade, low proliferative activity and positive receptors status. Furthermore, the breast cancer diagnosed through the MSP more frequently received a conservative surgery. The 5-year survival rate was 94% in the screen-detected group, versus 84% in the other group (p = 0.0001). The rate of 5-year event-free survival was 89% and 75% for the MSP participants and not participants, respectively (p = 0.0001).
  
  
  CONCLUSIONS
  Our data confirm a favourable outcome of screen-detected breast cancers in terms of five-year overall and event-free survival, which reflect the good quality assurance parameters of the MSP. Finally, a cancer registry should be implemented in every area covered by screening programs.
authors.affiliation: Dipartimento di Oncologia ed Ematologia, Università di Modena e Reggio Emilia, Italy. hbc@unimo.it
authors.forename: Laura
authors.initials: L
authors.lastname: Cortesi
authors.forename: Vincenzo E
authors.initials: VE
authors.lastname: Chiuri
authors.forename: Silvia
authors.initials: S
authors.lastname: Ruscelli
authors.forename: Valeria
authors.initials: V
authors.lastname: Bellelli
authors.forename: Rossella
authors.initials: R
authors.lastname: Negri
authors.forename: Ivan
authors.initials: I
authors.lastname: Rashid
authors.forename: Claudia
authors.initials: C
authors.lastname: Cirilli
authors.forename: Antonella
authors.initials: A
authors.lastname: Fracca
authors.forename: Ennio
authors.initials: E
authors.lastname: Gallo
authors.forename: Massimo
authors.initials: M
authors.lastname: Federico
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality* / Q000517:prevention & control; D005260:Female; D006801:Humans; D007558:Italy; D008327:Mammography; D008403:Mass Screening; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate