title: Importance of margin width in breast-conserving treatment of early breast cancer.
abstract: METHODS
  The association between margin width and ipsilateral breast tumour recurrence (IBTR, defined as invasive recurrence) was investigated in a population-based nationwide cohort of 11,900 patients undergoing breast-conserving therapy for invasive cancer.
  
  
  RESULTS
  The median follow-up was 4.9 years. The cumulative incidence of IBTR at 5 and 9 years was 2.4% and 5.9%, respectively. A final positive margin increased the risk of IBTR (HR 2.51; 95% CI 1.02-6.23). No decrease in IBTR with a wider negative margin compared to a narrow but negative margin was observed in the adjusted analysis of margin width (>0 to <2 mm vs. ≥2 to <5 mm vs. ≥5 mm (reference): HR 1.54 (CI 95% 0.81-2.93) vs. 0.95 (CI 95% 0.56-1.62) vs. 1). However, few patients had narrow margins. The factors associated with increased IBTR were young age (P < 0.001), >4 positive lymph nodes (P = 0.008) and re-excision (P = 0.003). A reduced risk of IBTR was observed with chemotherapy (P < 0.001), boost radiation (P = 0.023) and ER positivity (P < 0.001).
  
  
  CONCLUSIONS
  An overall low rate of IBTR was observed. A final positive margin was associated with a more than twofold risk of IBTR. There was no evidence for better local control with wider margins, but the data were insufficient to show whether narrow margins were as good as wider negative margins in terms of local control. J. Surg. Oncol. 2016;113:609-615. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Breast and Endocrine Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Anne
authors.initials: A
authors.lastname: Bodilsen
authors.affiliation: Danish Breast Cancer Cooperative Group, Copenhagen, Denmark.
authors.forename: Karsten
authors.initials: K
authors.lastname: Bjerre
authors.affiliation: Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Birgitte V
authors.initials: BV
authors.lastname: Offersen
authors.affiliation: Department of Pathology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Pernille
authors.initials: P
authors.lastname: Vahl
authors.affiliation: Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Nikolaj
authors.initials: N
authors.lastname: Amby
authors.affiliation: Breakthrough Research Unit Edinburgh Breast Unit, Western General Hospital, Edinburgh, United Kingdom.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Dixon
authors.affiliation: Danish Breast Cancer Cooperative Group, Copenhagen, Denmark.|Department of Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Bent
authors.initials: B
authors.lastname: Ejlertsen
authors.affiliation: Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Overgaard
authors.affiliation: Department of Surgery P, Breast Surgery Unit, Aarhus University Hospital/Randers Regional Hospital, Aarhus, Denmark.
authors.forename: Peer
authors.initials: P
authors.lastname: Christiansen
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D000072662:Margins of Excision; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D012042:Registries; D012307:Risk Factors; D016896:Treatment Outcome
keywords: boost; breast conserving therapy; invasive breast cancer; ipsilateral breast tumour recurrence; surgical margin