title: Prognostic value of lymph node micrometastases in breast cancer: a multicenter cohort study.
abstract: BACKGROUND
  To evaluate the prognostic meaning of lymph node micrometastases in breast cancer patients.
  
  
  METHODS
  Between January 2000 and January 2003, 1411 patients with a cT(1-2)N(0) invasive breast carcinoma underwent surgery in 7 hospitals in the Netherlands. Sentinel lymph node biopsy was done in all patients. Based on lymph node status, patients were divided into 4 groups: (p)N(0) (n = 922), (p)N(1micro) (n = 103), (p)N(1a) (n = 285), and (p)N(≥1b) (n = 101). Median follow-up was 6.4 years.
  
  
  RESULTS
  At the end of follow-up, 1121 women were still alive (79.4%), 184 had died (13.0%), and 106 were lost to follow-up (7.5%). Breast cancer recurred in 244 patients: distant metastasis (n = 165), locoregional relapse (n = 83), and contralateral breast cancer (n = 44). Following adjustment for possible confounding characteristics and for adjuvant systemic treatment, overall survival (OS) remained comparable for (p)N(0) and (p)N(1micro) and was significantly worse for (p)N(1a) and (p)N(≥1b) (hazard ratio [HR] 1.18; 95% confidence interval [95% CI] 0.58-2.39, HR 2.47; 95% CI 1.69-3.63, HR 4.36; 95% CI 2.70-7.04, respectively). Disease-free survival (DFS) was similar too in the (p)N(0) and (p)N(1micro) group, and worse for (p)N(1a) and (p)N(≥1b) (HR 0.96; 95% CI 0.56-1.67 vs HR 1.64; 95% CI 1.19-2.27, HR 2.95; CI 1.98-4.42). The distant metastases rate also did not differ significantly between the (p)N(0) and (p)N(1micro) group and was worse for (p)N(1a) and (p)N(≥1b) (HR 1.22; 95% CI 0.60-2.49, HR 2.26; 95% CI 1.49-3.40, HR 3.49; CI 2.12-5.77).
  
  
  CONCLUSIONS
  In breast cancer patients survival is not affected by the presence of micrometastatic lymph node involvement.
authors.affiliation: Department of Surgery, Diakonessenhuis Utrecht, Utrecht, The Netherlands. pgobardhan@amphia.nl
authors.forename: Paul D
authors.initials: PD
authors.lastname: Gobardhan
authors.forename: Sjoerd G
authors.initials: SG
authors.lastname: Elias
authors.forename: Eva V E
authors.initials: EV
authors.lastname: Madsen
authors.forename: Bob
authors.initials: B
authors.lastname: van Wely
authors.forename: Frits
authors.initials: F
authors.lastname: van den Wildenberg
authors.forename: Evert B M
authors.initials: EB
authors.lastname: Theunissen
authors.forename: Miranda F
authors.initials: MF
authors.lastname: Ernst
authors.forename: Marike C
authors.initials: MC
authors.lastname: Kokke
authors.forename: Carmen
authors.initials: C
authors.lastname: van der Pol
authors.forename: Inne H M
authors.initials: IH
authors.lastname: Borel Rinkes
authors.forename: Jan H
authors.initials: JH
authors.lastname: Wijsman
authors.forename: Vivian
authors.initials: V
authors.lastname: Bongers
authors.forename: Joost
authors.initials: J
authors.lastname: van Gorp
authors.forename: Thijs
authors.initials: T
authors.lastname: van Dalen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000401:mortality*; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy; D015996:Survival Rate; D016896:Treatment Outcome