title: What might explain deprivation-specific differences in the excess hazard of breast cancer death amongst screen-detected women? Analysis of patients diagnosed in the West Midlands region of England from 1989 to 2011.
abstract: BACKGROUND
  Breast cancer survival is higher in less deprived women, even amongst women whose tumor was screen-detected, but reasons behind this have not been comprehensively investigated.
  
  
  METHODS
  The excess hazard of breast cancer death in 20,265 women diagnosed with breast cancer, followed up to 2012, was estimated for screen-detected and non-screen-detected women, comparing more deprived to less deprived women using flexible parametric models. Models were adjusted for individual and tumor factors, treatment received and comorbidity. For screen-detected women, estimates were also corrected for lead-time and overdiagnosis.
  
  
  RESULTS
  The excess hazard ratio (EHR) of breast cancer death in the most deprived group, adjusted only for age and year of diagnosis, was twice that of the least deprived among screen-detected women (EHR=2.12, 95%CI 1.48-2.76) and 64% higher among non-screen-detected women (EHR=1.64, 95%CI 1.41-1.87). Adjustment for stage at diagnosis lowered these estimates by 25%. Further adjustment had little extra impact. In the final models, the excess hazard for the most deprived women was 54% higher (EHR=1.54, 95%CI 1.10-1.98) among screen-detected women and 39% higher (EHR=1.39, 95%CI 1.20-1.59) among non-screen-detected women.
  
  
  CONCLUSIONS
  A persistent socio-economic gradient in breast cancer-related death exists in this cohort, even for screen-detected women. The impact of differential lifestyles, management and treatment warrant further investigation.
authors.affiliation: Cancer Research UK Cancer Survival Group, Faculty of Epidemiology and Population Health, Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Melanie
authors.initials: M
authors.lastname: Morris
authors.affiliation: Cancer Research UK Cancer Survival Group, Faculty of Epidemiology and Population Health, Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Woods
authors.affiliation: Cancer Research UK Cancer Survival Group, Faculty of Epidemiology and Population Health, Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Bernard
authors.initials: B
authors.lastname: Rachet
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000401:mortality*; D015331:Cohort Studies; D015897:Comorbidity; D055088:Early Detection of Cancer; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000379:methods; D000069342:Medical Overuse; D008875:Middle Aged; D016016:Proportional Hazards Models; D012680:Sensitivity and Specificity; D012923:Social Class; D012959:Socioeconomic Factors; D016019:Survival Analysis
keywords: breast cancer; early diagnosis; population-based; socioeconomic inequalities; survival analysis