title: Swedish prospective multicenter trial evaluating sentinel lymph node biopsy after neoadjuvant systemic therapy in clinically node-positive breast cancer.
abstract: OBJECTIVE
  Patients with clinically node-positive breast cancer planned for neoadjuvant systemic therapy (NAST) may draw advantages from the nodal downstaging effect and reduce the extent of axillary surgery with sentinel lymph node biopsy (SLNB) performed after NAST. Since there are concerns about lower sentinel lymph node (SLN) detection and higher false-negative rates (FNR) in this setting, our aim was to define the accuracy of SLNB after NAST.
  
  
  METHODS
  This Swedish national multicenter trial prospectively recruited 195 breast cancer patients from ten hospitals with T1-T4d biopsy-proven node-positive disease planned for NAST between October 1, 2010 and December 31, 2015. Clinically node-negative axillary status after NAST was not mandatory. SLNB was always attempted and followed by a completion axillary lymph node dissection (ALND).
  
  
  RESULTS
  The SLN identification rate was 77.9% (152/195) but improved to 80.7% (138/171) with dual mapping. The median number of SLNs was two (range 1-5). A positive SLNB was found in 52% (79/152), almost 66% (52/79) of whom had additional positive non-sentinel lymph nodes. The overall pathologic nodal response rate was 33.3% (66/195). The overall FNR was 14.1% (13/92) but decreased to 4% (2/50) when only patients with two or more sentinel nodes were analyzed.
  
  
  CONCLUSIONS
  In biopsy-proven node-positive breast cancer, SLNB after NAST is feasible even though the identification rate is lower than in clinically node-negative patients. Since the overall FNR is unacceptably high, the omission of ALND should only be considered if two or more SLNs are identified.
authors.affiliation: Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden. linda.holmstrand-zetterlund@sll.se.|Department of Surgery, Södersjukhuset, 118 83, Stockholm, Sweden. linda.holmstrand-zetterlund@sll.se.
authors.forename: Linda Holmstrand
authors.identifier: http://orcid.org/0000-0002-4774-5945
authors.initials: LH
authors.lastname: Zetterlund
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.|Departmnet of Breast and Endocrine Surgery, Karolinska University Hospital, 171 76, Stockholm, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Frisell
authors.affiliation: Department of Radiology, Södersjukhuset, 118 83, Stockholm, Sweden.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Zouzos
authors.affiliation: Department of Clinical Science, Intervention and Technology, Division of Radiography, Karolinska Institutet, Stockholm, Sweden.|Department of Radiology, Karolinska University Hospital Huddinge, 141 86, Stockholm, Sweden.
authors.forename: Rimma
authors.initials: R
authors.lastname: Axelsson
authors.affiliation: Department of Oncology, Karolinska Institutet, Cancer Center Karolinska and Karolinska University Hospital, 171 76, Stockholm, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hatschek
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.|Department of Surgery, Capio St Göran's Hospital, 112 81, Stockholm, Sweden.
authors.forename: Jana
authors.initials: J
authors.lastname: de Boniface
authors.affiliation: Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.|Department of Surgery, Södersjukhuset, 118 83, Stockholm, Sweden.
authors.forename: Fuat
authors.initials: F
authors.lastname: Celebioglu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018943:Anthracyclines / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001365:Axilla; D001943:Breast Neoplasms / Q000628:therapy*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods; D008207:Lymphatic Metastasis; D008408:Mastectomy / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013548:Sweden; D043823:Taxoids / Q000627:therapeutic use*
chemical_list: D018943:Anthracyclines; D047072:Aromatase Inhibitors; D043823:Taxoids
keywords: Breast cancer; False-negative rate; Identification rate; Neoadjuvant systemic therapy; Node-positive; Sentinel lymph node biopsy