title: Incidence and prognostic influence of lymph node micrometastases in rectal cancer.
abstract: OBJECTIVE
  The aim of this study was to determine the rate of lymph node micrometastases and evaluate their prognostic significance in rectal cancer.
  
  
  METHODS
  Patients with either Dukes A or B rectal carcinoma who had undergone curative resection by either low anterior resection or abdominal perineal resection between 1991 and 2000 were selected from a prospectively collated database. None of the patients had metastasis at the time of surgery and none received adjuvant or neoadjuvant therapy. A single section from each lymph node was stained with haematoxylin and eosin (H+E) and with CAM 5.2 by immunohistochemistry. Statistical analyses were performed with Chi-square test.
  
  
  RESULTS
  A total of 774 lymph nodes with a median of 14 lymph nodes per patient were examined, from a cohort of 56 patients with a median age of 66 years. In the 56 patients in whom lymph node metastases were not detected by haematoxylin-eosin staining, cytokeratin staining was positive in 15 lymph nodes from 10 patients. Nine patients had disease recurrence at a median follow-up of 98 months. The presence of lymph node micrometastases by immunohistochemistry did not predict either disease-free (p=0.44) or overall survival (p=0.63).
  
  
  CONCLUSIONS
  Immunohistochemical staining detects micrometastases in rectal cancer which are not observed with H+E staining. However, no significant relationship was observed between disease relapse and rectal micrometastases detected by immunohistochemistry.
authors.affiliation: Surgical Professorial Unit, Department of Surgery, Our Lady of Lourdes Hospital Drogheda, County Louth, Ireland. fjfleming@rcsi.ie
authors.forename: F J
authors.initials: FJ
authors.lastname: Fleming
authors.forename: A J
authors.initials: AJ
authors.lastname: Hayanga
authors.forename: F
authors.initials: F
authors.lastname: Glynn
authors.forename: H
authors.initials: H
authors.lastname: Thakore
authors.forename: E
authors.initials: E
authors.lastname: Kay
authors.forename: P
authors.initials: P
authors.lastname: Gillen
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D012189:Retrospective Studies