title: Clinical impact of false-negative sentinel lymph nodes in breast cancer.
abstract: OBJECTIVE
  To evaluate the incidence of false-negative (FN) sentinel lymph node (SLN) cases, their correlation with a series of clinico-pathologic parameters and their impact on adjuvant treatment indications and on clinical axillary relapse in the setting of a multicentric clinical trial comparing SLN biopsy with axillary lymph node dissection (ALND).
  
  
  METHODS
  A series of 697 patients with primary breast cancer < or = 3 cm were randomized to SLN biopsy associated with ALND (ALND arm) or to SLN biopsy followed by ALND only if the SLN was metastatic (SLN arm). The FN SLN rate was assessed in the ALND arm. A series of 11 clinico-pathological parameters were tested for a possible association with FN results. The indications for adjuvant treatments were evaluated by considering both the FN nodal stages, as indicated by the SLN, and the true positive axillary status, as indicated by completion ALND. The occurrence of clinically evident axillary recurrences was evaluated in the two arms.
  
  
  RESULTS
  The FN rate was 16.7%. Of the clinico-pathologic parameters tested, only a tumour size < or = 2 cm and the presence of a single metastatic axillary node was significantly associated with a risk of FN (p = 0.033 and p = 0.018, respectively). The FN SLN would have led to different adjuvant therapy indications in 12/18 cases. At 56 months, no clinically evident axillary nodal recurrences were present in the ALND arm patients, whereas one case of axillary recurrence was detected in the SLN arm patients.
  
  
  CONCLUSIONS
  FN SLN biopsy is not uncommon, especially in the presence of a small primary tumour with a single nodal metastasis. An FN finding can lead to less than optimal adjuvant treatment. However, the clinical impact of FN in terms of axillary recurrence at 56 months was minimal.
authors.affiliation: Clinica Chirurgica II, University of Padova, Via Giustiniani 2, 35128 Padova, Italy. giorgio.zavagno@unipd.it
authors.forename: G
authors.initials: G
authors.lastname: Zavagno
authors.forename: P
authors.initials: P
authors.lastname: Del Bianco
authors.forename: H
authors.initials: H
authors.lastname: Koussis
authors.forename: G
authors.initials: G
authors.lastname: Artioli
authors.forename: P
authors.initials: P
authors.lastname: Carraro
authors.forename: G L
authors.initials: GL
authors.lastname: De Salvo
authors.forename: R
authors.initials: R
authors.lastname: Mencarelli
authors.forename: V
authors.initials: V
authors.lastname: Belardinelli
authors.forename: G
authors.initials: G
authors.lastname: Marconato
authors.forename: D
authors.initials: D
authors.lastname: Nitti
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D003657:Decision Making; D018572:Disease-Free Survival; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D015994:Incidence; D008197:Lymph Node Excision / Q000379:methods; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D021701:Sentinel Lymph Node Biopsy