Abstract | AIMS: Recent reports suggest that genetic examination of K-ras or p53 mutation is more sensitive for the detection of occult lymph node metastasis in colorectal carcinomas than conventional examination by haematoxylin and eosin (H & E) staining or immunohistochemistry for gene products. The aim of this study was, first, to define the microscopic characteristics of metastatic cancer cells in lymph nodes stained by the anti- cytokeratin antibody CAM5.2 for cytokeratins 8 and 18, and, second, to compare the detection rate of occult lymph node metastasis for immunohistochemical vs genetic methods. METHODS AND RESULTS: K-ras mutations were first examined in primary tumours of seven cases which showed distant metastasis or local recurrence within 5 years of the initial surgery in spite of the original reporting of no lymph node metastasis by routine H & E staining. K-ras mutations were positive in three cases in primary tumours and lymph nodes, and the remaining four primary tumours were negative for p53 mutation as well as K-ras mutation. Therefore, genetic analysis of occult lymph node metastasis was uninformative, but occult metastasis was detected by cytokeratin staining in two of these four cases. Comparative study of cytokeratin-positive cells was performed on each of the 43 lymph nodes from three cases with K-ras mutations. Cancer cells were detected in 28 of the 43 lymph nodes (65.1%) by cytokeratin staining and in 10 of the 43 corresponding lymph nodes (23.3%) by genetic analysis. Artefactual contamination by cancer cells was present in eight of the 28 cytokeratin positive lymph nodes, and three of the eight nodes were genetically positive. CONCLUSIONS: This study suggests that cytokeratin immunohistochemistry is more sensitive and specific for the detection of occult lymph node metastasis than genetic diagnosis by K-ras mutation in cases with genetic alterations as well as in cases without them.
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Authors | M Sasaki, H Watanabe, J R Jass, Y Ajioka, M Kobayashi, K Hatakeyama |
Journal | Histopathology
(Histopathology)
Vol. 32
Issue 3
Pg. 199-208
(Mar 1998)
ISSN: 0309-0167 [Print] England |
PMID | 9568504
(Publication Type: Comparative Study, Journal Article)
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Chemical References |
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Topics |
- Aged
- Aged, 80 and over
- Case-Control Studies
- Colorectal Neoplasms
(genetics, metabolism, pathology)
- Female
- Genes, p53
- Genes, ras
- Humans
- Immunoenzyme Techniques
(statistics & numerical data)
- Keratins
(metabolism)
- Lymphatic Metastasis
(diagnosis, genetics, physiopathology)
- Male
- Middle Aged
- Mutation
- Prognosis
- Sensitivity and Specificity
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