title: Urban-rural differences in the management of screen-detected invasive breast cancer and ductal carcinoma in situ in victoria.
abstract: BACKGROUND
  At least one-third of primary breast cancers in Australia are discovered by population-based mammographic screening. The aim of this study was to determine whether there were any differences in the surgical treatment of women diagnosed with breast cancer by BreastScreen Victoria between urban and rural populations and to investigate temporal changes in their pattern of care.
  
  
  METHODS
  An analysis of women diagnosed with breast cancer (invasive and non-invasive) by BreastScreen Victoria from 1993 to 2000 was conducted. Descriptive analyses of the proportion of women undergoing each surgical treatment type over time were carried out. Logistic regression was used to assess the effect of urban-rural residence on each treatment outcome while accounting for possible confounding factors.
  
  
  RESULTS
  Rural women with invasive breast cancer were less likely to undergo breast-conserving surgery (BCS) compared with urban women (odds ratio, 0.42; 95% confidence interval, 0.35-0.50). The same was also true for rural women with ductal carcinoma in situ (odds ratio, 0.53; 95% confidence interval, 0.29-0.96). This difference was independent of patient and tumour characteristics, including tumour size, surgeon caseload, patient's age and socioeconomic status. It also persisted over time despite a steady overall increase in use of BCS for both invasive and non-invasive cancers over the study period.
  
  
  CONCLUSIONS
  Among Victorian women with screen-detected breast cancer, urban women consistently had higher rates of BCS compared with rural women despite increased overall adoption of BCS. Reasons for this disparity are still unclear and warrant further investigation.
authors.affiliation: School of Medicine, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Kok
authors.forename: Jiun-Horng
authors.initials: JH
authors.lastname: Chang
authors.forename: Bircan
authors.initials: B
authors.lastname: Erbas
authors.forename: Ashley
authors.initials: A
authors.lastname: Fletcher
authors.forename: Anne M
authors.initials: AM
authors.lastname: Kavanagh
authors.forename: Michael A
authors.initials: MA
authors.lastname: Henderson
authors.forename: Dorota M
authors.initials: DM
authors.lastname: Gertig
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008327:Mammography; D008403:Mass Screening / Q000379:methods*; D008408:Mastectomy / Q000379:methods*; D008875:Middle Aged; D012189:Retrospective Studies; D012424:Rural Population; D016896:Treatment Outcome; D014505:Urban Population; D014739:Victoria / Q000453:epidemiology