title: Lymph node isolated tumor cells and micrometastases in pathological stage I non-small cell lung cancer: prognostic significance.
abstract: OBJECTIVE
  To determine the prevalence and prognostic significance of lymph node micrometastases and isolated tumor cells (ITC) in patients submitted for radical resection for pathological stage I non-small cell lung cancer (NSCLC).
  
  
  METHODS
  From January 1998 through December 2005, 87 consecutive pT1-2, pN0 NSCLC patients were enrolled. Surgical specimens were submitted to pathological routine examinations to define histotype, grade, stage, vascular invasion, necrosis and tumor proliferative index. A total of 694 regional lymph nodes were examined by means of serial sections stained with hematoxylin and eosin and labelled by immunohistochemistry (antibody AE1/AE3, DAKO). Relationships between these parameters and patients' prognosis were investigated.
  
  
  RESULTS
  By histological examination, there were 36 squamous-cell carcinoma, 38 adenocarcinoma and 13 large-cell carcinoma. Micrometastases and ITC were detected in 19 lymph nodes (2.7%) of 14 patients (16%). Significant correlation was observed between micrometastases or ITC and adenocarcinoma (p=0.03) and the absence of necrosis (p=0.05). No relationship was demonstrated between micrometastases or ITC and T-status, vascular invasion or proliferative index (p>0.05). Median follow-up was 3.2 (range 0.25-8.6) years. Two- and 5-year disease-free survival was similar for patients with and without micrometastases or ITC (79% and 64% vs 81% and 64%, respectively). Recurrence occurred in three patients with (two local, 66%) and in 21 patients without micrometastases or ITC (three local, 14%) (p=0.186). By multivariate analysis only T-status was demonstrated to be a significant prognostic factor.
  
  
  CONCLUSIONS
  Micrometastases or ITC to regional lymph nodes are demonstrated to be not a rare aspect of pathological stage I resected lung cancer. In our series, the presence of lymph nodes micrometastases does not affect long-term disease-free survival.
authors.affiliation: Department of Thoracic Surgery, University of Eastern Piedmont, Novara, Italy. ottaviorena@libero.it
authors.forename: Ottavio
authors.initials: O
authors.lastname: Rena
authors.forename: Luca
authors.initials: L
authors.lastname: Carsana
authors.forename: Silvia
authors.initials: S
authors.lastname: Cristina
authors.forename: Esther
authors.initials: E
authors.lastname: Papalia
authors.forename: Fabio
authors.initials: F
authors.lastname: Massera
authors.forename: Luca
authors.initials: L
authors.lastname: Errico
authors.forename: Cristina
authors.initials: C
authors.lastname: Bozzola
authors.forename: Caterina
authors.initials: C
authors.lastname: Casadio
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D016019:Survival Analysis