title: Detection of micrometastasis in the sentinel lymph nodes in breast cancer.
abstract: BACKGROUND
  The axillary lymph node (ALN) status is still the most important prognostic factor in the staging and treatment of breast cancer. Intraoperative lymphatic mapping and sentinel lymphadenectomy techniques were investigated in patients with early-stage breast cancer who did not have clinically palpable ALNs.
  
  
  METHODS
  Forty-four patients with breast cancer underwent a sentinel lymph node biopsy (SLNB), followed by a complete axillary lymphadenectomy. Sentinel lymph nodes (SLNs) were detected by means of so-called 2-way mapping with coloring matter and an isotope. Our standard protocol for evaluating metastasis in SLNs included a frozen section at 1 level for reverse transcription polymerase chain reaction (RT-PCR), plus a paraffin section at 1 level for immunohistochemistry (IHC) of cytokeratin 19, while the rest were evaluated by hematoxylin-eosin (H&E) staining.
  
  
  RESULTS
  SLNs were identified in 42 (95%) of 44 patients. Twenty-one patients had no metastasis in SLNs; however, ALN metastasis was found in 3 patients. Of these 3 patients, 2 had micrometastasis detected by means of either IHC or RT-PCR. Therefore the false-negative rate was decreased from 7% (3/44) to 2% (1/44). Furthermore, of the remaining 18 ALN-negative patients, micrometastasis was detected by means of either IHC or RT-PCR in 7 (39%) patients.
  
  
  CONCLUSIONS
  We suggest that SLNB is recommended to detect micrometastasis by means of H&E staining, IHC, and RT-PCR. Omitting ALN dissection referred by SLNB should be avoided if SLNs were evaluated only by H&E staining, and/or IHC without RT-PCR.
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ishida
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kitamura
authors.forename: Junko
authors.initials: J
authors.lastname: Kinoshita
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kuwahara
authors.forename: Keizo
authors.initials: K
authors.lastname: Sugimachi
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000556:secondary*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007633:Keratins / Q000235:genetics*; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021701:Sentinel Lymph Node Biopsy
chemical_list: D012333:RNA, Messenger; D007633:Keratins