title: Size of breast cancer metastases in axillary lymph nodes: clinical relevance of minimal lymph node involvement.
abstract: BACKGROUND
  Overt ipsilateral axillary lymph node metastases of breast cancer are the most significant prognostic indicators for women who have undergone surgery, yet the clinical relevance of minimal involvement (isolated tumor cells and micrometastases) of these nodes is uncertain.
  
  
  METHODS
  We evaluated biologic features, adjuvant treatment recommendations, and prognosis for 1,959 consecutive patients with pT1-3, pN0, minimal lymph node involvement (pN1mi or pN0i+), or pN1a (single positive node) and M0, who were operated on and counseled for medical therapy from April 1997 to December 2000.
  
  
  RESULTS
  Patients with pN1a and pN1mi/pN0i+, when compared with patients with pN0 disease, were more often prescribed anthracycline-containing chemotherapy (39.1% v 33.2% v 6.1%, respectively; P < .0001) and were less likely to receive endocrine therapy alone (9.8% v 19.4% v 41.9%, respectively; P < .0001). At the multivariate analysis, a statistically significant difference in disease-free survival (DFS) and in the risk of distant metastases was observed for patients with pN1a versus pN0 disease (hazard ratio [HR] = 2.04; 95% CI, 1.46 to 2.86; P < .0001 for DFS; HR = 2.32; 95% CI, 1.42 to 3.80; P = .0007 for distant metastases) and for patients with pN1mi/pN0i+ versus pN0 disease (HR = 1.58; 95% CI, 1.01 to 2.47; P = .047 for DFS; HR = 1.94; 95% CI, 1.04 to 3.64; P = .037 for distant metastases).
  
  
  CONCLUSIONS
  Even minimal involvement of a single axillary node in breast cancer significantly correlates with worse prognosis compared with no axillary node involvement. Further studies are required before widespread modification of clinical practice.
authors.affiliation: Division of Medical Oncology, Department of Medicine, Istituto Europeo di Oncologia, Via Ripamonti 435, 20141, Milan, Italy. marco.colleoni@ieo.it
authors.forename: Marco
authors.initials: M
authors.lastname: Colleoni
authors.forename: Nicole
authors.initials: N
authors.lastname: Rotmensz
authors.forename: Giulia
authors.initials: G
authors.lastname: Peruzzotti
authors.forename: Patrick
authors.initials: P
authors.lastname: Maisonneuve
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mazzarol
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pruneri
authors.forename: Alberto
authors.initials: A
authors.lastname: Luini
authors.forename: Mattia
authors.initials: M
authors.lastname: Intra
authors.forename: Paolo
authors.initials: P
authors.lastname: Veronesi
authors.forename: Viviana
authors.initials: V
authors.lastname: Galimberti
authors.forename: Rosalba
authors.initials: R
authors.lastname: Torrisi
authors.forename: Anna
authors.initials: A
authors.lastname: Cardillo
authors.forename: Aron
authors.initials: A
authors.lastname: Goldhirsch
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Viale
mesh_terms: D000328:Adult; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D011379:Prognosis