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Updated: Aug 10, 2026

Adaptation of Semiautomated Circulating Tumor Cell (CTC) Assays for Clinical and Preclinical Research Applications
Published on: February 28, 2014
Immunocytochemical detection using CDX2: An aid for discerning tumor involvement in ascites cytology
Masako Kobayashi1, Yuji Ueyama, Hayao Nakanishi
1Department of Pathology and Molecular Diagnosis, Aichi Cancer Center, Nagoya, Japan.
Background:
Although ascites cytology is important for therapeutic strategies, it is difficult to distinguish cancer infiltration from reactive mesothelial proliferation in some patients. In this study, the authors applied CDX2 immunocytochemistry to improve diagnostic accuracy.
Methods:
The authors examined the distribution of CDX2 expression in carcinoma specimens using paraffin-embedded tissues from various organs from 549 cancer patients. CDX2 immunostaining was applied to the 116 ascites specimens.
Results:
CDX2 expression was detected in a restricted range of cancers, with the vast majority of them originating from the gastrointestinal tract and pancreas. When applied to ascites specimens, no positive reactions were detected in any of the 81 cytology-negative and molecular genetic analysis-negative specimens. By contrast, 28 of 35 specimens diagnosed as suspicious for malignancy or malignancy showed a positive reaction. Furthermore, the authors found that a nuclear-positive reaction was easily evaluated, even with a high level of background staining, and single cancer cells in 10(6) normal cells could be detected.
Conclusion:
Results suggest that CDX2 is a specific and sensitive marker to detect gastrointestinal and pancreatic malignancies in ascites cytology.
