title: Prognostic significance of histologically detected lymph node micrometastases of sizes between 0.2 and 2 mm in colorectal cancer.
abstract: OBJECTIVE
  Minimal lymph node involvement is a potential prognostic factor in colorectal cancer. The International Union Against Cancer defined tumour deposits between 0.2 and 2 mm as micrometastases and clusters and single-cell infiltrations below this cutoff as isolated tumour cells. Nevertheless, only a minority of studies discriminated metastatic involvements according to this definition.
  
  
  METHODS
  In order to investigate the prognostic significance of micrometastases (0.2-2 mm), we performed a retrospective study enrolling 44 routinely diagnosed micrometastatic cases within 15 years which represent about 1% of our cases. These cases have been re-evaluated.
  
  
  RESULTS
  Seven of the micrometastatic cases turned out to be macrometastases after step sectioning. Complete follow-up was available in 33 remaining cases. Collections of node-negative and macrometastatic cases served as control groups. The Kaplan-Meier curves of macro- and micrometastatic cases showed a similar adverse course (p = 0.830) especially during the first 40 months. The 5-year-survival rates were 51, 60 and 64 months for macro-, micrometastatic and node-negative cases, respectively. The difference in overall survival, however, reached only a statistical trend and was not significant (p = 0.137). After re-evaluation with step sections and cytokeratin immunohistochemistry out of an initial 91 node-negative cases, 11 (12%) cases were identified with isolated tumour cells and one (1%) case with a micrometastasis.
  
  
  CONCLUSIONS
  Our data show that micro- and macrometastatic colorectal cancers show very similar survival rates. Therefore, efforts to improve the detection of lymph node micrometastases seem to be justified.
authors: Institute of Pathology, Klinikum Augsburg, Stenglinstrasse 2, 86156 Augsburg, Germany. Bruno.Maerkl@klinikum-augsburg.de
authors: Bruno
authors: B
authors: Märkl
authors: C
authors: C
authors: Herbst
authors: C
authors: C
authors: Cacchi
authors: T
authors: T
authors: Schaller
authors: I
authors: I
authors: Krammer
authors: G
authors: G
authors: Schenkirsch
authors: A
authors: A
authors: Probst
authors: H
authors: H
authors: Spatz
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D061206:Neoplasm Micrometastasis / Q000473:pathology*; D011379:Prognosis