title: Risk factors for local recurrence after breast-conserving surgery.
abstract: BACKGROUND
  It is not clear whether risk factors for local recurrence after breast-conserving surgery differ in women having surgery for in situ or invasive cancer. Furthermore, the Nottingham Prognostic Index (NPI) and Nottingham Histological Grade (NHG) have been little studied as determinants of local recurrence risk.
  
  
  METHODS
  In a case-control study (491 cases and 1098 controls) nested within a cohort of 7502 women who had surgery for in situ or invasive cancer of the breast, patient characteristics, tumour characteristics and treatment-related variables were evaluated as risk factors for local recurrence.
  
  
  RESULTS
  Multivariate conditional logistic regression analyses showed that age below 40 years, tumour multicentricity and an unclear or unknown surgical margin were significant risk factors for local recurrence. Radiotherapy to the breast and adjuvant hormone therapy were protective. Cancer in situ was not associated with a higher risk of local recurrence than invasive cancer (odds ratio 1.0, 95 per cent confidence interval 0.8 to 1.3). NHG and NPI were not helpful in determining risk of local recurrence.
  
  
  CONCLUSIONS
  Margin status, age, tumour multicentricity, and use of radiotherapy and adjuvant hormone therapy were important determinants of risk of local recurrence. With the exception of surgical margin, variables related to the quality of surgical management did not predict risk of local recurrence.
authors.affiliation: Department of Surgery, The Karolinska Institute, Stockholm Söder Hospital, Stockholm, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Fredriksson
authors.forename: G
authors.initials: G
authors.lastname: Liljegren
authors.forename: M
authors.initials: M
authors.lastname: Palm-Sjövall
authors.forename: L-G
authors.initials: LG
authors.lastname: Arnesson
authors.forename: S O
authors.initials: SO
authors.lastname: Emdin
authors.forename: T
authors.initials: T
authors.lastname: Fornander
authors.forename: A
authors.initials: A
authors.lastname: Lindgren
authors.forename: H
authors.initials: H
authors.lastname: Nordgren
authors.forename: I
authors.initials: I
authors.lastname: Idvall
authors.forename: M
authors.initials: M
authors.lastname: Holmqvist
authors.forename: L
authors.initials: L
authors.lastname: Holmberg
authors.forename: J
authors.initials: J
authors.lastname: Frisell
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D002278:Carcinoma in Situ / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D016022:Case-Control Studies; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology / Q000473:pathology; D012307:Risk Factors; D016896:Treatment Outcome