title: Outcome after ipsilateral breast tumor recurrence in patients who receive accelerated partial breast irradiation.
abstract: BACKGROUND
  The objective of this study was to examine clinical outcomes and patterns of failure in patients with early stage breast cancer who developed an ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy (BCT) using accelerated partial breast irradiation (APBI).
  
  
  METHODS
  In total, 1440 patients (1449 tumors) with early stage breast cancer who underwent BCT were treated with the MammoSite device to deliver APBI (34 Gray [Gy] in 3.4-Gy fractions). One thousand two hundred fifty-five patients (87%) had invasive breast cancer (IBC) (median tumor size, 10 mm), and 194 patients (13%) had ductal carcinoma in situ (DCIS) (median tumor size, 8 mm). The median follow-up was 60 months.
  
  
  RESULTS
  Fifty patients (3.5%) developed an IBTR for a 5-year actuarial rate of 3.61% (3.65% for IBC and 3.36% for DCIS). It was determined that 36 recurrences (72%) represented new primary cancers, and 14 recurrences (28%) represented recurrences of the index lesion. Of the 32 recurrences with known histology, 78% were IBC, and 22% were DCIS. After IBTR, 28 of 38 patients (74%) underwent salvage mastectomy, and 9 of 38 patients (26%) had a second attempt at BCT. Adjuvant therapies included tamoxifen in 8 patients (16%) and systemic chemotherapy in 6 patients (12%). The 3-year rates of disease-free survival, cause-specific survival, and overall survival after IBTR were 58.7%, 92.1%, and 80.5%, respectively.
  
  
  CONCLUSIONS
  With 5 years of follow-up, APBI produced clinical outcomes and patterns of failure comparable to those achieved with whole breast irradiation. Patients who developed an IBTR after APBI had excellent 3-year survival outcomes after salvage treatments.
authors.affiliation: Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan, USA.
authors.forename: Chirag
authors.initials: C
authors.lastname: Shah
authors.forename: Frank
authors.initials: F
authors.lastname: Vicini
authors.forename: Martin
authors.initials: M
authors.lastname: Keisch
authors.forename: Henry
authors.initials: H
authors.lastname: Kuerer
authors.forename: Peter
authors.initials: P
authors.lastname: Beitsch
authors.forename: Bruce
authors.initials: B
authors.lastname: Haffty
authors.forename: Maureen
authors.initials: M
authors.lastname: Lyden
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy; D001943:Breast Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000628:therapy*; D016609:Neoplasms, Second Primary / Q000601:surgery; D018714:Radiotherapy, Adjuvant; D016879:Salvage Therapy; D017211:Treatment Failure; D016896:Treatment Outcome