title: Clinical implications of occult metastases and isolated tumor cells in sentinel and non-sentinel lymph nodes in early breast cancer patients: serial step section analysis with long-term follow-up.
abstract: BACKGROUND
  This study was designed to clarify retrospectively the clinical significance of occult metastases in both sentinel lymph nodes (SLNs) and non-SLNs in patients with early breast cancer.
  
  
  METHODS
  A total of 109 (80.1%) of 136 women with breast cancer who had consecutively undergone SLN biopsy (176 lymph nodes) were intraoperatively diagnosed as being free of SLN involvement. SLNs were routinely examined by hematoxylin-eosin (HE) staining of one to four frozen sections per node. Sixty-four (58.7%) of these patients also underwent backup axillary dissection. For the 109 patients, all formalin-fixed, paraffin-embedded tissues of SLNs and non-SLNs were entirely cut into 5-μm-thick sections. All serial step sections at 85-μm intervals were stained with HE and immunohistochemistry with pancytokeratin.
  
  
  RESULTS
  Occult metastases in SLNs and non-SLNs were detected in 25 (23%) and 10 (16%) patients, respectively. The presence of occult SLN metastasis was marginally correlated with T-factor (P=0.06), and predictive factors for occult non-SLN metastases were tumor nuclear grade (P=0.039). With a median follow-up of 86 months, disease-free survival (P=0.3) or overall survival (P=0.8) did not differ between the patients with and without occult SLN metastases, regardless of backup axillary lymph node dissection.
  
  
  CONCLUSIONS
  SLN or non-SLN occult metastases detected by serial step sections at 85-μm intervals did not have significant prognostic implications.
authors: Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors: Takashi
authors: T
authors: Takeshita
authors: Hitoshi
authors: H
authors: Tsuda
authors: Tomoyuki
authors: T
authors: Moriya
authors: Tamio
authors: T
authors: Yamasaki
authors: Hideki
authors: H
authors: Asakawa
authors: Shigeto
authors: S
authors: Ueda
authors: Kazuhiko
authors: K
authors: Sato
authors: Shinsuke
authors: S
authors: Aida
authors: Seiichi
authors: S
authors: Tamai
authors: Osamu
authors: O
authors: Matsubara
authors: Kazuo
authors: K
authors: Hase
authors: Junji
authors: J
authors: Yamamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000473:pathology* / Q000556:secondary* / Q000628:therapy; D018275:Carcinoma, Lobular / Q000401:mortality / Q000473:pathology* / Q000556:secondary* / Q000628:therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D060787:Neoplasm Grading; D011379:Prognosis; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D016019:Survival Analysis