title: [Mediastinal lymph nodes micro-metastases in patients with clinical stage I-II lung cancer].
abstract: OBJECTIVE
  To investigate micro-metastasis in mediastinal lymph nodes (mLN) of patients with clinical stage I approximately II lung cancer and its clinical significance.
  
  
  METHODS
  A total of 181 mLN from 32 lung cancer patients in clinical stage I approximately II were collected during operation and their frozen sections at two different levels were examined immunohistochemically (IHC) with an anti-epithelial cell monoclonal antibody Ber-Ep4. Routine HE staining was done for comparison. The results were processed by Chi-square tests in SPSS 10.0 soft ware.
  
  
  RESULTS
  Fifteen of the 32 patients (46.9%) were found to have micro-metastasis in 21 of 181 mLN (11.6%) examined by immunohistochemical staining though routine histopathological examinations were negative. Of those 15 cases, micro-metastasis was detected in 9 only by IHC and in 6 both by IHC and HE stainings. The positive rate of micro-metastasis in N0, N1, and N2 stratified by routine pathology was 36.8% (7/19), 33.3% (2/6) and 85.7% (6/7), respectively (N0 vs N2, P < 0.05). When stratified according to clinical staging (cTNM), pathological staging (pTNM) and pathological staging on the basis of IHC (iTNM), the frequencies of N2 cases were 0, 18.8% and 46.9%, respectively (differences among the three groups: P < 0.01). Nine cases reported as N0(7) and N1(2) by routine histopathological examination were found to have micro-metastasis in mLN by IHC staining, therefore they were actually N2 cases.
  
  
  CONCLUSIONS
  IHC staining with a monoclonal antibody specific for epithelial cells (Ber-Ep4) is more sensitive in the detection of mediastinal micro-metastais than routine HE staining. Underestimation of the extent of mLN metastasis by cTNM and/or pTNM stagings frequently exists in patients with clinically early lung cancer.
authors.affiliation: Department of Thoracic Surgery, Cancer Institute (Hospital), Chinese Academy of Medical Sciences and Peking Union Medical University, Beijing 100021, China. Maoys@hotmail.com
authors.forename: You-sheng
authors.initials: YS
authors.lastname: Mao
authors.forename: De-chao
authors.initials: DC
authors.lastname: Zhang
authors.forename: Hong-tu
authors.initials: HT
authors.lastname: Zhang
authors.forename: Yun-tian
authors.initials: YT
authors.lastname: Sun
authors.forename: Xiao-hang
authors.initials: XH
authors.lastname: Zhao
authors.forename: Xiu-ying
authors.initials: XY
authors.lastname: Liu
authors.forename: Guo-lian
authors.initials: GL
authors.lastname: Wei
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000556:secondary; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000556:secondary; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D009367:Neoplasm Staging
chemical_list: D000911:Antibodies, Monoclonal; C117805:Ber-EP4 monoclonal antibody