title: Increased risk of locoregional recurrence for women with T1-2N0 triple-negative breast cancer treated with modified radical mastectomy without adjuvant radiation therapy compared with breast-conserving therapy.
abstract: OBJECTIVE
  To evaluate the risk of locoregional recurrence (LRR) associated with locoregional treatment of women with primary breast cancer tumors negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (triple-negative breast cancer [TNBC]).
  
  
  METHODS
  Patients diagnosed with TNBC were identified from a cancer registry in a single institution (n=768). LRR-free survival was estimated using Kaplan-Meier analysis. The Cox proportional hazards regression model was used to determine risk of LRR on the basis of locoregional management: breast-conserving therapy (BCT; ie, lumpectomy and adjuvant radiation therapy [RT]) and modified radical mastectomy (MRM) in the TNBC population and T1-2N0 subgroup.
  
  
  RESULTS
  At a median follow-up of 7.2 years, 77 patients (10%) with TNBC developed LRR. Five-year LRR-free survival was 94%, 85%, and 87% in the BCT, MRM, and MRM + RT groups, respectively (P < .001). In multivariate analysis, MRM (compared with BCT), lymphovascular invasion and lymph node positivity were associated with increased LRR. Conversely, adjuvant chemotherapy was associated with decreased risk of LRR. For patients with T1-2N0 tumors, 5-year LRR-free survival was 96% and 90% in the BCT and MRM groups, respectively (P = .027), and MRM was the only independent prognostic factor associated with increased LRR compared with BCT (hazard ratio, 2.53; 95% CI, 1.12 to 5.75; P = .0264).
  
  
  CONCLUSIONS
  Women with T1-2N0 TNBC treated with MRM without RT have a significant increased risk of LRR compared with those treated with BCT. Prospective studies are warranted to investigate the benefit of adjuvant RT after MRM in TNBC.
authors.affiliation: Cross Cancer Institute and University of Alberta, Edmonton, Alberta, Canada. bassam.abdulkarim@mcgill.ca
authors.forename: Bassam S
authors.initials: BS
authors.lastname: Abdulkarim
authors.forename: Julie
authors.initials: J
authors.lastname: Cuartero
authors.forename: John
authors.initials: J
authors.lastname: Hanson
authors.forename: Jean
authors.initials: J
authors.lastname: Deschênes
authors.forename: David
authors.initials: D
authors.lastname: Lesniak
authors.forename: Siham
authors.initials: S
authors.lastname: Sabri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D015411:Mastectomy, Modified Radical / Q000009:adverse effects* / Q000401:mortality; D015412:Mastectomy, Segmental / Q000009:adverse effects / Q000401:mortality; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human