title: Independent prognostic value of screen detection in invasive breast cancer.
abstract: BACKGROUND
  Mammographic screening has led to a proportional shift toward earlier-stage breast cancers at presentation. We assessed whether the method of detection provides prognostic information above and beyond standard prognostic factors and investigated the accuracy of predicted overall and breast cancer-specific survival by the computer tool Adjuvant! among patients with screen-detected, interval, and nonscreening-related carcinomas.
  
  
  METHODS
  We studied 2592 patients with invasive breast cancer who were treated at the Netherlands Cancer Institute from January 1, 1990, through December 31, 2000. Overall and breast cancer-specific survival probabilities among patients with mammographically screen-detected (n = 958), interval (n = 417), and nonscreening-related (n = 1217) breast carcinomas were compared. Analyses were adjusted for clinicopathologic characteristics and adjuvant systemic therapy. Because of gradual implementation of population-based screening in the Netherlands, analyses were stratified a priori according to two periods of diagnosis. All statistical tests were two-sided.
  
  
  RESULTS
  Screen detection was associated with reduced mortality (adjusted hazard ratio for all-cause mortality = 0.74, 95% confidence interval = 0.63 to 0.87, P < .001, and adjusted hazard ratio for breast cancer-specific mortality = 0.62, 95% confidence interval = 0.50 to 0.78, P < .001, respectively) compared with nonscreening-related detection. The absolute adjusted reduction in breast cancer-specific mortality was 7% at 10 years. The prognostic value of the method of detection was independent of the period of diagnosis and was similar across tumor size and lymph node status categories, indicating its prognostic value beyond stage migration. Adjuvant! underestimated breast cancer-specific survival in patients with screen-detected (-3.2%) and interval carcinomas (-5.4%).
  
  
  CONCLUSIONS
  Screen detection was found to be independently associated with better prognosis for overall and breast cancer-specific survival and to provide prognostic information beyond stage migration among patients with invasive breast cancer. We propose that the method of detection should be taken into account when estimating individual prognosis.
authors.affiliation: Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital Amsterdam, The Netherlands.
authors.forename: Stella
authors.initials: S
authors.lastname: Mook
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Van 't Veer
authors.forename: Emiel J
authors.initials: EJ
authors.lastname: Rutgers
authors.forename: Peter M
authors.initials: PM
authors.lastname: Ravdin
authors.forename: Anthonie O
authors.initials: AO
authors.lastname: van de Velde
authors.forename: Flora E
authors.initials: FE
authors.lastname: van Leeuwen
authors.forename: Otto
authors.initials: O
authors.lastname: Visser
authors.forename: Marjanka K
authors.initials: MK
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008327:Mammography; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models