title: Regional recurrence in breast cancer patients with sentinel node micrometastases and isolated tumor cells.
abstract: OBJECTIVE
  The impact of axillary treatment in daily practice on 5-year regional recurrence rate in breast cancer patients with isolated tumor cells or micrometastases in the sentinel node (SLN).
  
  
  BACKGROUND
  Axillary dissection is recommended in patients with tumor-positive SLNs. But, in recent studies, regional recurrence rates seemed low if dissection was omitted.
  
  
  METHODS
  We identified all patients in The Netherlands with invasive breast cancer who had an SLN biopsy before 2006, favorable primary tumor characteristics, and node-negative disease, isolated tumor cells or micrometastases as final nodal status. The primary endpoint was regional recurrence rate. To investigate differences in recurrence rates between patients with and without axillary treatment, a proportional hazard regression was carried out correcting for potential confounders.
  
  
  RESULTS
  In total, 857 patients with node-negative disease, 795 patients with isolated tumor cells, and 1028 patients with micrometastases in the SLN were included. Without axillary treatment, the 5-year regional recurrence rates were 2.3%, 2.0%, and 5.6%, respectively. Compared with patients who underwent axillary treatment, the adjusted hazard ratio for regional recurrence in patients who underwent an SLN procedure only was 1.08 (95% CI, 0.23-4.98) for node-negative disease, 2.39 (95% CI, 0.67-8.48) for isolated tumor cells, and 4.39 (95% CI, 1.46-13.24) for micrometastases. Doubling of tumor size, grade 3 and negative hormone receptor status were also significantly associated with recurrence.
  
  
  CONCLUSIONS
  Not performing axillary treatment in patients with SLN micrometastases is associated with an increased 5-year regional recurrence rate. Axillary treatment is recommended in patients with SLN micrometastases and unfavorable tumor characteristics.
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Manon J
authors.initials: MJ
authors.lastname: Pepels
authors.forename: Maaike
authors.initials: M
authors.lastname: de Boer
authors.forename: Peter
authors.initials: P
authors.lastname: Bult
authors.forename: Jos A
authors.initials: JA
authors.lastname: van Dijck
authors.forename: Carolien H
authors.initials: CH
authors.lastname: van Deurzen
authors.forename: Marian B
authors.initials: MB
authors.lastname: Menke-Pluymers
authors.forename: Paul J
authors.initials: PJ
authors.lastname: van Diest
authors.forename: George F
authors.initials: GF
authors.lastname: Borm
authors.forename: Vivianne C G
authors.initials: VC
authors.lastname: Tjan-Heijnen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla / Q000473:pathology / Q000601:surgery; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D059248:Chemoradiotherapy; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D021701:Sentinel Lymph Node Biopsy