title: Timing of sentinel lymph node biopsy in patients receiving neoadjuvant chemotherapy for breast cancer.
abstract: OBJECTIVE
  To address optimal timing of sentinel lymph node biopsy (SLNB) in breast cancer patients undergoing neoadjuvant treatment.
  
  
  METHODS
  The study population included 117 patients with locally advanced cancer with clinically negative nodes treated with primary chemotherapy. Group 1 underwent SLNB and completion axillary lymph node dissection (ALND) in conjunction with lumpectomy/mastectomy, after neoadjuvant treatment (n = 31). Group 2 underwent SLNB followed by neoadjuvant therapy and subsequently surgery and completion of ALNDs (n = 58). Group 3 was treated using the same sequence as group 2, however, completion ALND was performed only for patients with positive sentinel lymph nodes (SLNs) (n = 28).
  
  
  RESULTS
  SLN identification was lowest in group 1 compared to groups 2 and 3 (87% and 98.8% respectively; P = <0.05). The highest false negative rate was in group 1 (15.8% compared with 0% in group 2).
  
  
  CONCLUSIONS
  Neoadjuvant treatment lowers the SLN identification rate, possibly due to fibrosis within the axilla, and increases the false negative rate due to downstaging. SLN biopsy prior to chemotherapy could give a more accurate evaluation of axillary status, unaffected by any previous therapeutic intervention.
authors.affiliation: Department of Surgery and Surgical Oncology and the Breast Service, Chaim Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Moshe Zvi
authors.initials: MZ
authors.lastname: Papa
authors.forename: Douglas
authors.initials: D
authors.lastname: Zippel
authors.forename: Bella
authors.initials: B
authors.lastname: Kaufman
authors.forename: Shani
authors.initials: S
authors.lastname: Shimon-Paluch
authors.forename: Ady
authors.initials: A
authors.lastname: Yosepovich
authors.forename: Bernice
authors.initials: B
authors.lastname: Oberman
authors.forename: Siegal
authors.initials: S
authors.lastname: Sadetzki
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D021701:Sentinel Lymph Node Biopsy; D013997:Time Factors