title: Ipsilateral axillary recurrence after breast conservative surgery: The protective effect of whole breast radiotherapy.
abstract: Whole breast radiotherapy (WBRT) is one of the possible reasons for the low rate of axillary recurrence after breast-conserving surgery (BCS).
  
  
  
  We retrospectively collected data from 4,129 consecutive patients with breast cancer ⩽2cm and negative sentinel lymph node who underwent BCS between 1997 and 2007. We compared the risk of axillary lymph node recurrence between patients treated by WBRT (n=2939) and patients who received partial breast irradiation (PBI; n=1,190) performed by a single dose of electron intraoperative radiotherapy.
  
  
  
  Median tumour diameter was 1.1cm in both WBRT and PBI. Women who received WBRT were significantly younger and expressed significantly more multifocality, extensive in situ component, negative oestrogen receptor status and HER2 over-expression than women who received PBI. After a median follow-up of 8.3years, 37 and 28 axillary recurrences were observed in the WBRT and PBI arm, respectively, corresponding to a 10-year cumulative incidence of 1.3% and 4.0% (P<0.001). Multivariate analysis resulted in a hazard ratio of 0.30 (95% CI 0.17-0.51) in favour of WBRT.
  
  
  
  In this large series of women with T1 breast cancer and negative sentinel lymph node treated by BCS, WBRT lowered the risk of axillary recurrence by two thirds as compared to PBI.
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy. Electronic address: gentilini.oreste@hsr.it.
authors.forename: Oreste
authors.initials: O
authors.lastname: Gentilini
authors.affiliation: Epidemiology and Biostatistics Division, European Institute of Oncology, Milano, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Botteri
authors.affiliation: Radiotherapy Division, European Institute of Oncology, Milano, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Leonardi
authors.affiliation: Epidemiology and Biostatistics Division, European Institute of Oncology, Milano, Italy.
authors.forename: Nicole
authors.initials: N
authors.lastname: Rotmensz
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy.
authors.forename: Jose
authors.initials: J
authors.lastname: Vila
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy.
authors.forename: Nickolas
authors.initials: N
authors.lastname: Peradze
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy.
authors.forename: Maria Virginia
authors.initials: MV
authors.lastname: Thomazini
authors.affiliation: Radiotherapy Division, European Institute of Oncology, Milano, Italy; University of Milan, European Institute of Oncology, Italy.
authors.forename: Barbara Alicja
authors.initials: BA
authors.lastname: Jereczek
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Galimberti
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Luini
authors.affiliation: Breast Surgery Division, European Institute of Oncology, Milano, Italy; Epidemiology and Biostatistics Division, European Institute of Oncology, Milano, Italy; Radiotherapy Division, European Institute of Oncology, Milano, Italy; University of Milan, European Institute of Oncology, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Veronesi
authors.affiliation: Scientific Directorate, European Institute of Oncology, Milano, Italy; University of Milan, European Institute of Oncology, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Orecchia
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D012189:Retrospective Studies
keywords: Axillary recurrence; Breast-conserving surgery; Partial breast irradiation; Whole breast radiotherapy