title: Impact of a mammography screening programme on the breast cancer population of the Region of Valencia (Spain).
abstract: OBJECTIVE
  Randomised clinical trials with a control arm of non-screened patients are nowadays ethically impossible. The aim of this study was to establish the impact of mammography screening on a non-selected population.
  
  
  METHODS
  Between January 1993 and December 2002, 3662 patients were included, 2313 in the screened group and 1349 in the unscreened group.
  
  
  RESULTS
  55.3% of the screened patients were diagnosed in stage I vs. 26.1% in the non-screened group. The proportion of stage III-IV was 4.6% and 19.8% for the screened and unscreened groups respectively (p<0.001). 48.8% in the screening group were submitted to mastectomy vs. 66.4% of the unscreened patients (p<0.001). Overall survival was superior for the prevalent cases in the screening group, with a relative risk of 0.49, and was not significant for the incident cases.
  
  
  CONCLUSIONS
  Diagnosis of breast cancer in the mammography screening programme of the Region of Valencia significantly increases conservative surgery rates and suggests an improvement in survival in prevalent cases. The increased rate of early stages in these patients could be the main reason of this benefit.
authors.affiliation: Oncology and Hematology Department, Hospital Clínico Universitario de Valencia, Valencia, Spain. japfidalgo@msn.com
authors.forename: Jose Alejandro
authors.initials: JA
authors.lastname: Pérez-Fidalgo
authors.forename: Josefa
authors.initials: J
authors.lastname: Miranda
authors.forename: Isabel
authors.initials: I
authors.lastname: Chirivella
authors.forename: Josefa
authors.initials: J
authors.lastname: Ibáñez
authors.forename: Begona
authors.initials: B
authors.lastname: Bermejo
authors.forename: Carmen
authors.initials: C
authors.lastname: Pons
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Melchor
authors.forename: Ana
authors.initials: A
authors.lastname: Santaballa
authors.forename: Francisco
authors.initials: F
authors.lastname: Martínez-Ruiz
authors.forename: Ana
authors.initials: A
authors.lastname: Lluch
authors.forename: Dolores
authors.initials: D
authors.lastname: Salas
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000453:epidemiology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015986:Confounding Factors, Epidemiologic; D055088:Early Detection of Cancer; D004967:Estrogens; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening / Q000706:statistics & numerical data*; D008408:Mastectomy / Q000379:methods / Q000706:statistics & numerical data; D008875:Middle Aged; D009367:Neoplasm Staging; D009376:Neoplasms, Hormone-Dependent / Q000000981:diagnostic imaging / Q000453:epidemiology; D011374:Progesterone; D015397:Program Evaluation; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D016019:Survival Analysis
chemical_list: D004967:Estrogens; D011374:Progesterone