title: Omitting radiation therapy in women with triple-negative breast cancer leads to worse breast cancer-specific survival.
abstract: OBJECTIVE
  To examine locoregional recurrence (LRR) and breast cancer-specific survival (BCSS) after breast-conserving therapy (BCT) or mastectomy (ME) with or without radiation therapy (RT) in triple-negative breast cancer (TNBC).
  
  
  METHODS
  We identified non-metastatic TNBC cases from a single institution database. BCT, ME with RT (ME + RT) and ME only were compared with respect to LRR and BCSS. Cox regression models were used to analyze the association between prognostic factors and outcome.
  
  
  RESULTS
  439 patients fulfilled the inclusion criteria. Median follow-up was 10.2 years (interquartile range 7.9; 12.4 years). Patients in the BCT (n = 239), ME + RT (n = 116) and ME only (n = 84) group differed with respect to age, pT, pN, lymphovascular invasion, lymph node dissection and chemotherapy administration. Ten-year LRR rates were seven percent, three percent and eight percent for the BCT, ME + RT and ME only group, respectively. pN was associated with LRR. In multivariable analysis LRR were significantly lower in the ME + RT group compared to the BCT and the ME only group (p 0.037 and 0.020, respectively). Ten year BCSS was 87%, 84% and 75% for the BCT, ME + RT and ME only group, respectively. pT, pN, lymph node dissection, lymphovascular invasion and the administration of chemotherapy were associated with BCSS. In multivariable analysis BCSS was significantly lower in the ME only group compared to the BCT group and the ME + RT group (p 0.047 and 0.003, respectively).
  
  
  CONCLUSIONS
  TNBC patients treated with ME without adjuvant RT showed significant lower BCSS compared to patients treated with BCT or ME + RT and significant more LRR compared to ME + RT when corrected for known clinicopathological prognostic factors.
authors.affiliation: KU Leuven - University of Leuven, Department of Oncology, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of Radiation Oncology, Herestraat 49, B-3000, Leuven, Belgium. Electronic address: isabelle.kindts@uzleuven.be.
authors.forename: I
authors.initials: I
authors.lastname: Kindts
authors.affiliation: KU Leuven - University of Leuven, Department of Oncology, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of Radiation Oncology, Herestraat 49, B-3000, Leuven, Belgium. Electronic address: pieterjan.buelens@uzleuven.be.
authors.forename: P
authors.initials: P
authors.lastname: Buelens
authors.affiliation: Leuven Biostatistics and Statistical Bioinformatics Centre (L-Biostat), KU Leuven University, Kapucijnenvoer 35, B-3000, Leuven, Belgium. Electronic address: annouschka.laenen@kuleuven.be.
authors.forename: A
authors.initials: A
authors.lastname: Laenen
authors.affiliation: KU Leuven - University of Leuven, Department of Oncology, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of Radiation Oncology, Herestraat 49, B-3000, Leuven, Belgium. Electronic address: erik.vanlimbergen@uzleuven.be.
authors.forename: E
authors.initials: E
authors.lastname: Van Limbergen
authors.affiliation: KU Leuven - University of Leuven, Department of Oncology, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of Radiation Oncology, Herestraat 49, B-3000, Leuven, Belgium. Electronic address: hilde.janssen@uzleuven.be.
authors.forename: H
authors.initials: H
authors.lastname: Janssen
authors.affiliation: KU Leuven - University of Leuven, Department of Oncology, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of General Medical Oncology, Herestraat 49, B-3000, Leuven, Belgium. Electronic address: hans.wildiers@uzleuven.be.
authors.forename: H
authors.initials: H
authors.lastname: Wildiers
authors.affiliation: KU Leuven - University of Leuven, Department of Oncology, B-3000, Leuven, Belgium; University Hospitals Leuven, Department of Radiation Oncology, Herestraat 49, B-3000, Leuven, Belgium. Electronic address: caroline.weltens@uzleuven.be.
authors.forename: C
authors.initials: C
authors.lastname: Weltens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium / Q000453:epidemiology; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008408:Mastectomy / Q000379:methods; D015412:Mastectomy, Segmental / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D011446:Prospective Studies; D018714:Radiotherapy, Adjuvant / Q000401:mortality; D012189:Retrospective Studies; D064726:Triple Negative Breast Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D055815:Young Adult
keywords: Breast-conserving therapy; Indication; Mastectomy; Radiation therapy; Triple-negative breast cancer