title: Effect of treatment and mammography detection on breast cancer survival over time: 1990-2007.
abstract: BACKGROUND
  The extent to which improvements over time in breast cancer survival are related to earlier detection by mammography or to more effective treatments is not known.
  
  
  METHODS
  At a comprehensive cancer care center, the authors conducted a retrospective cohort study of women ages 50 to 69 years who were diagnosed with invasive breast cancer (stages I through III) and were followed over 3 periods (1990-1994, 1995-1999, and 2000-2007). Data were abstracted from patient charts and included detection method, diagnosis, treatment, and follow-up for vital status in the institutional breast cancer registry (n = 2998). The method of detection was categorized as patient or physician detected or mammography detected. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for 5-year disease-specific survival in relation to detection method and treatment factors, and differences in survival were analyzed using the Kaplan-Meier method.
  
  
  RESULTS
  Fifty-eight percent of breast cancers were mammography detected, and 42% were patient or physician detected; 56% of tumors were stage I, 31% were stage II, and 13% were stage III. The average length of follow-up was 10.71 years. The combined 5-year disease-specific survival rate was 89% from 1990 to 1994, 94% from 1995 to 1999, and 96% from 2000 to 2007 (P < .001). In an adjusted model, mammography detection (HR, 0.43; 95% CI, 0.27-0.70), hormone therapy (HR, 0.47; 95% CI, 0.30-0.75), and taxane-containing chemotherapy (HR, 0.61; 95% CI, 0.37-0.99) were significantly associated with a decreased risk of disease-specific mortality.
  
  
  CONCLUSIONS
  Better breast cancer survival over time was related to mammography detection, hormone therapy, and taxane-containing chemotherapy. Treatment improvements alone are not sufficient to explain the observed survival improvements over time.
authors: Department of Oncology, Swedish Cancer Institute, Seattle, Washington.
authors: Henry G
authors: HG
authors: Kaplan
authors: HealthStat Consulting, Seattle, Washington.|Department of Epidemiology, University of Washington School of Public Health, Seattle, Washington.
authors: Judith A
authors: JA
authors: Malmgren
authors: Department of Oncology, Swedish Cancer Institute, Seattle, Washington.
authors: Mary K
authors: MK
authors: Atwood
authors: Center for Pharmacoepidemiology and Pharmacoeconomic Research, University of Illinois at Chicago, Chicago, Illinois.
authors: Gregory S
authors: GS
authors: Calip
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality* / Q000628:therapy; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D012189:Retrospective Studies; D018426:SEER Program; D012959:Socioeconomic Factors; D016019:Survival Analysis; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: adjuvant chemotherapy; breast cancer; mammography; regression modeling; survival