title: Overall survival in patients with a re-excision following breast conserving surgery compared to those without in a large population-based cohort.
abstract: OBJECTIVE
  To investigate the overall survival of invasive breast cancer patients with primary breast conserving surgery (BCS) followed by re-excision compared to those with primary BCS only. The Dutch re-excision indications are less stringent compared to other European and Northern American countries (Society of Surgical Oncology-American Society for Radiation Oncology (SSO/ASTRO) guideline).
  
  
  METHODS
  Retrospective analyses in women <75years with breast cancer stage pT1-T3 treated by BCS and radiotherapy between 1999 and 2012 from a population-based database. The national guideline recommends to reserve re-excision for invasive tumours showing 'more than focally positive' margin since 2002. Patients were divided into 'primary BCS only', 're-excision by BCS', and 're-excision by mastectomy'. Multivariable Cox regression analysis was adjusted for patient and systemic treatment characteristics.
  
  
  RESULTS
  A total of 11,695 patients were included of which 2156 (18.4%) underwent re-excision. Median time of follow-up was 61months (interquartile range (IQR) 26-101). The 5-year overall survival rates in the 'primary BCS only', 're-excision by BCS' and 're-excision by mastectomy' group were 92%, 95% and 91%, respectively. The 10-year overall survival rates were 81%, 82% and 79%, respectively (P=0.20). After multivariable analyses no significant association was observed between use of and type of re-excision and overall survival.
  
  
  CONCLUSIONS
  The overall survival of breast cancer patients with a re-excision did not significantly differ from the survival of women who underwent primary BCS only. Advising re-excision only for those tumours showing 'more than focally positive' resection margin appears safe, supposing the long-term safety of the recent SSO/ASTRO guideline that more cautiously recommended re-excision for tumours showing 'ink on tumour'.
authors.affiliation: Department of Surgery, Erasmus MC Cancer Institute, Postbus 5201, 3008 AE Rotterdam, The Netherlands. Electronic address: e.l.vos@erasmusmc.nl.
authors.forename: Elvira L
authors.initials: EL
authors.lastname: Vos
authors.affiliation: Department of Medical Oncology, Erasmus MC Cancer Institute, Postbus 5201, 3008 AE Rotterdam, The Netherlands. Electronic address: a.jager@erasmusmc.nl.
authors.forename: Agnes
authors.initials: A
authors.lastname: Jager
authors.affiliation: Department of Surgery, Erasmus MC Cancer Institute, Postbus 5201, 3008 AE Rotterdam, The Netherlands. Electronic address: c.verhoef@erasmusmc.nl.
authors.forename: Cornelis
authors.initials: C
authors.lastname: Verhoef
authors.affiliation: Research Department, Comprehensive Cancer Centre the Netherlands, Postbus 231, 5600 AE Eindhoven, The Netherlands. Electronic address: A.Voogd@iknl.nl.
authors.forename: Adri C
authors.initials: AC
authors.lastname: Voogd
authors.affiliation: Department of Surgery, Erasmus MC Cancer Institute, Postbus 5201, 3008 AE Rotterdam, The Netherlands. Electronic address: l.koppert@erasmusmc.nl.
authors.forename: Linetta B
authors.initials: LB
authors.lastname: Koppert
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality* / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000401:mortality* / Q000601:surgery*; D018275:Carcinoma, Lobular / Q000401:mortality / Q000601:surgery; D005260:Female; D006801:Humans; D008408:Mastectomy / Q000379:methods; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012086:Reoperation; D012189:Retrospective Studies; D016019:Survival Analysis
keywords: Breast cancer; Breast conserving surgery; Overall survival; Re-excision