CDX1, CDX2 and A33 as markers for metastatic colorectal adenocarcinoma
Research type
Research Study
Full title
A comparison of CDX1, CDX2 and A33 as markers of metastatic colorectal adenocarcinoma
IRAS ID
140532
Contact name
Newton A. C. S. Wong
Contact email
Sponsor organisation
Research and Innovation, University Hospitals Bristol NHS Foundation Trust
Research summary
Metastatic carcinoma of an unknown primary presents in 3 to 5% of patients newly diagnosed with malignancy. Adenocarcinomas (i.e. cancers of glandular tissue) represent a major proportion of this group but they can originate from various organs. Because the treatment of adenocarcinomas is dependent on the site from which they arise, identifying the tissue of origin is essential. Radiological imaging is often insufficient and adenocarcinomas usually show similar appearance microscopically.
Adenocarcinoma of colon is one of the most common cancers and it is currently commonly identified by a CDX2 molecule present in the cells. However, in a proportion of these cancers CDX2 is absent and furthermore it may be expressed by other cancers e.g. gallbladder and pancreas.
Previous reports have indicated two molecules characteristic to the gastrointestinal tract – A33 and CDX1 – which are also found in colorectal adenocarcinomas. Recent developments have provided antibodies specifically for these two molecules and allow the comparison of their expression with CDX2, an evaluation not reported in literature to date. This study, therefore, is aimed at comparing specificity and sensitivity of CDX1, CDX2 and A33 as markers of metastatic colorectal adenocarcinoma.
One hundred and thirty two samples of liver metastases of adenocarcinoma will be anonymously cut from paraffin tissue blocks obtained from the Department of Histopathology in Bristol Royal Infirmary. These will include 73 samples from confirmed colorectal primary tumours, 28 from pancreas/biliary tract, 19 from oesophagus/stomach, 4 from breast and 7 from lung and one from ovary.
These anonymised sections will each be stained for CDX1, CDX2 and A33 molecules. The stains will be evaluated whether there is expression of the given molecule in the tumour. The results will be compared to determine the usefulness of each molecule as a diagnostic marker.REC name
South Central - Oxford C Research Ethics Committee
REC reference
14/SC/0155
Date of REC Opinion
12 Mar 2014
REC opinion
Favourable Opinion