title: Impact of mammography detection on the course of breast cancer in women aged 40-49 years.
abstract: OBJECTIVE
  To analyze trends in detection method related to breast cancer stage at diagnosis, treatments, and outcomes over time among 40-49-year-old women.
  
  
  METHODS
  i This study was institutional review board approved, with a waiver of informed consent, and HIPAA compliant. A longitudinal prospective cohort study was conducted of women aged 40-49 years who had primary breast cancer, during 1990-2008, and were identified and tracked by a dedicated registry database (n = 1977). Method of detection--patient detected (PtD), physician detected (PhysD), or mammography detected (MamD)--was chart abstracted. Disease-specific survival and relapse-free survival statistics were calculated by using the Kaplan-Meier method for stage I-IV breast cancer.
  
  
  RESULTS
  A significant increase in the percentage of MamD breast cancer over time (28%-58%) and a concurrent decline in patient and physician detected (Pt/PhysD) breast cancer (73%-42%) (Pearson x(2) = 72.72, P < .001) were observed over time from 1990 to 2008, with an overall increase in lower-stage disease detection and a decrease in higher-stage disease. MamD breast cancer patients were more likely to undergo lumpectomy (67% vs 48% of Pt/PhysD breast cancer patients) and less likely to undergo modified radical mastectomy (25% vs 47% of the Pt/PhysD breast cancer patients) (P < .001). Uncorrected for stage, 13% of MamD breast cancer patients underwent surgery and chemotherapy versus 22% of Pt/PhysD breast cancer patients (P < .001), and 31% of MamD breast cancer patients underwent surgery, radiation therapy, and chemotherapy versus 59% of Pt/PhysD breast cancer patients (x(2) = 305.13, P < .001). Analyzing invasive cancers only, 5-year relapse-free survival for MamD breast cancer patients was 92% versus 88% for Pt/PhysD patients (log-rank test, 12.47; P < .001).
  
  
  CONCLUSIONS
  Increased mammography-detected breast cancer over time coincided with lower-stage disease detection resulting in reduced treatment and lower rates of recurrence, adding factors to consider when evaluating the benefits of mammography screening of women aged 40-49 years.
authors.affiliation: HealthStat Consulting, 12025 Ninth Ave NW, Seattle, WA 98177, USA. jmalmgren@seanet.com
authors.forename: Judith A
authors.initials: JA
authors.lastname: Malmgren
authors.forename: Jay
authors.initials: J
authors.lastname: Parikh
authors.forename: Mary K
authors.initials: MK
authors.lastname: Atwood
authors.forename: Henry G
authors.initials: HG
authors.lastname: Kaplan
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D016009:Chi-Square Distribution; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008327:Mammography; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011446:Prospective Studies; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome