title: Omitting re-excision for focally positive margins after breast-conserving surgery does not impair disease-free and overall survival.
abstract: OBJECTIVE
  In contrast to other countries, the Dutch breast cancer guideline does not recommend re-excision for focally positive margins after breast-conserving surgery (BCS) in invasive tumor and does recommend whole-breast irradiation including boost. We investigated whether omitting re-excision as compared to performing re-excision affects prognosis with a retrospective population-based cohort study.
  
  
  METHODS
  The total cohort included 32,119 women with primary BCS for T1-T3 breast cancer diagnosed between 2003 and 2008 from the nationwide Netherlands cancer registry. The subcohort included 10,433 patients in whom the resection margins were registered. Outcome measures were 5-year ipsilateral breast tumor recurrence (IBTR) rate, 5-year disease-free survival (DFS) rate, and 10-year overall survival (OS) rate.
  
  
  RESULTS
  In the total cohort, 25,878 (80.6%) did not have re-excision, 2368 (7.4%) had re-excision by BCS, and 3873 (12.1%) had re-excision by mastectomy. Five-year IBTR rates were 2.1, 2.8, and 2.9%, respectively (p = 0.001). In the subcohort, 7820 (75.0%) had negative margins without re-excision, 492 (4.7%) had focally positive margins without re-excision, 586 (5.6%) had focally positive margins and underwent re-excision, and 1535 (14.7%) had extensively positive margins and underwent re-excision. Five-year IBTR rate was 2.3, 2.9, 1.1, and 2.9%, respectively (p = 0.099). Compared to omitting re-excision, performing re-excision for focally positive margins was associated with lower risk of IBTR (adjusted HR 0.30, 95% CI 0.11-0.82), but not with DFS (adjusted HR 0.83 95% CI 0.59-1.17) nor with OS (adjusted HR 1.17 95% CI 0.87-1.59).
  
  
  CONCLUSIONS
  Omitting re-excision in breast cancer patients for focally positive margins after BCS does not impair DFS and OS, provided that whole-breast irradiation including boost is given.
authors.affiliation: Department of Oncological Surgery, Erasmus MC Cancer Institute, DHA-102, PO Box 2400, 3000, Rotterdam, The Netherlands.
authors.forename: Elvira L
authors.initials: EL
authors.lastname: Vos
authors.affiliation: Department of Research, Netherlands Comprehensive Cancer Organisation (IKNL), PO Box 19079, 3501, Utrecht, The Netherlands.|Department of Health Technology and Services Research, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, PO Box 217, 7500, Enschede, The Netherlands.
authors.forename: Sabine
authors.initials: S
authors.lastname: Siesling
authors.affiliation: Department of Radiotherapy, Erasmus MC Cancer Institute, PO Box 5201, 3008, Rotterdam, The Netherlands.
authors.forename: Margreet H A
authors.initials: MHA
authors.lastname: Baaijens
authors.affiliation: Department of Oncological Surgery, Erasmus MC Cancer Institute, DHA-102, PO Box 2400, 3000, Rotterdam, The Netherlands.
authors.forename: Cornelis
authors.initials: C
authors.lastname: Verhoef
authors.affiliation: Department of Medical Oncology, Erasmus MC Cancer Institute, PO Box 5201, 3008, Rotterdam, The Netherlands.
authors.forename: Agnes
authors.initials: A
authors.lastname: Jager
authors.affiliation: Department of Research, Netherlands Comprehensive Cancer Organisation (IKNL), PO Box 19079, 3501, Utrecht, The Netherlands.|Department of Epidemiology, Maastricht University, PO Box 616, 6200, Maastricht, The Netherlands.
authors.forename: Adri C
authors.initials: AC
authors.lastname: Voogd
authors.affiliation: Department of Oncological Surgery, Erasmus MC Cancer Institute, DHA-102, PO Box 2400, 3000, Rotterdam, The Netherlands. l.koppert@erasmusmc.nl.
authors.forename: Linetta B
authors.initials: LB
authors.lastname: Koppert
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008408:Mastectomy; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology; D018365:Neoplasm, Residual / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D009426:Netherlands / Q000453:epidemiology; D011379:Prognosis
keywords: Breast-conserving surgery; Disease-free survival; Ipsilateral breast tumor recurrence; Overall survival; Re-excision; Re-operation; Resection margins