title: Prospective evaluation of the feasibility of sentinel lymph node biopsy in breast cancer patients with negative axillary conversion after neoadjuvant chemotherapy.
abstract: OBJECTIVE
  Tumor response to neoadjuvant chemotherapy (NAC) may adversely affect the identification and accuracy rate of sentinel lymph node biopsy (SLNB). This study was conducted to evaluate the feasibility of SLNB in node-positive breast cancer patients with negative axillary conversion after NAC.
  
  
  METHODS
  Ninety-six patients with positive nodes at presentation were prospectively enrolled. (18)Fluorodeoxyglucose-positron emission tomography ((18)F-FDG PET) and ultrasonography were performed before and after NAC. A metastatic axillary lymph node was defined as positive if it was positive upon both (18)F-FDG PET and ultrasonography, while it was considered negative if it was negative upon both (18)F-FDG PET and ultrasonography.
  
  
  RESULTS
  After NAC, 55 cases (57.3%) became clinically node-negative, while 41 cases (42.7%) remained node-positive. In the entire cohort, the sentinel lymph node (SLN) identification and false-negative rates were 84.3% (81/96) and 18.4% (9/49), respectively. In the negative axillary conversion group, the results of SLNB showed an 85.7% (48/55) identification rate and 16.7% (4/24) false-negative rate.
  
  
  CONCLUSIONS
  For breast cancer patients with clinically positive nodes at presentation, it is difficult to conclude whether the SLN accurately represents the metastatic status of all axillary lymph nodes, even after clinically negative node conversion following NAC.
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hy-De
authors.initials: HD
authors.lastname: Lee
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Gwe
authors.initials: SG
authors.lastname: Ahn
authors.affiliation: Department of Surgery, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea.
authors.forename: Seung Ah
authors.initials: SA
authors.lastname: Lee
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hak Min
authors.initials: HM
authors.lastname: Lee
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Joon
authors.initials: J
authors.lastname: Jeong
keywords: Breast neoplasms; Neoadjuvant therapy; Predictive value of tests; Sentinel lymph node biopsy