November 5, 2023

CDX-2 is a gene that encodes for a protein known as Caudal Type Homeobox 2. It is a member of the caudal-related homeobox transcription factor gene family. This protein is crucial for embryonic development, particularly in forming the small and large intestines. It acts as a transcription factor that regulates the expression of genes involved in the development and maintenance of intestinal epithelial cells, playing a significant role in intestinal cell differentiation and proliferation.

What does CDX-2 do?

• Intestinal development: CDX-2 is crucial for the development of the intestines during embryogenesis.
• Maintenance and repair: CDX-2 controls the expression of genes essential for the maintenance and repair of the intestinal epithelium.

Types of cells that normally express CDX-2

CDX-2 is expressed by epithelial cells throughout the small and large intestines which includes the colon and rectum. It is also expressed by tissues that have undergone a noncancerous process called intestinal metaplasia where cells change to become more like those in the intestine.

Types of noncancerous tumors that express CDX-2

Most noncancerous tumours arising in the small and large intestines will express CDX-2. The most common of these noncancerous tumours are colorectal adenomas or polyps.

Types of cancers that express CDX-2

• Colorectal cancer: Most types of cancers arising in the colon and rectum will express CDX-2 including adenocarcinoma, mucinous adenocarcinoma, well differentiated neuroendocrine tumour, and poorly differentiated neuroendocrine carcinoma.
• Small intestinal cancer: Besides colorectal cancer, other gastrointestinal cancers, such as those originating in the small intestine, may express CDX-2. These include ampullary adenocarcinoma and non-ampullary adenocarcinoma.
• Metastatic cancers of gastrointestinal origin: Metastases from primary gastrointestinal cancers such as colorectal adenocarcinoma typically express CDX-2, which can help in identifying the origin of the cancer.

Detection of CDX-2 in tissue samples

Pathologists commonly perform a test called immunohistochemistry (IHC) to see CDX-2-expressing cells in a tissue sample. This test provides spatial information about where the protein is expressed within tissue samples making it invaluable for diagnosing and monitoring conditions related to the gastrointestinal tract.

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

Other helpful resources

Atlas of pathology