CA 19-9
The carbohydrate antigen 19-9 ( CA 19-9 ) is a glycoprotein used in oncology as a tumor marker with a half-life of 4 to 8 days. It is verified by laboratory tests using an immunoassay (normal value depending on the assay <37–40 kU / l). The maximum achievable diagnostic sensitivity is 95%. The presence of CA 19-9 is linked to the Lewis blood group . People who have the blood type Lewis negative (a- / b-) do not express CA 19-9.
Differential diagnosis
CA 19-9 has the highest sensitivity in pancreatic carcinoma (in pancreatic carcinomas with a diameter of <3 cm, the marker is positive in about 50% of cases and in cases of a tumor diameter of> 3 cm in about 85-90%). In pancreatic cancer, the height of the tumor marker correlates with the tumor size.
In the following other tumor diseases, increases in the serum CA-19-9 level are occasionally found:
- Bile duct carcinoma (≈70%)
- Gastric cancer (≈40%)
- Colon cancer (≈35%)
Non-malignant diseases that can lead to an increase in CA-19-9 levels:
- Pancreatitis
- Diseases of the biliary tract
- Liver disease
- Nicotine abuse
Clinical application
The measurement of CA 19-9 is used in tumors (if its level was increased before treatment) to monitor therapy and progress. The CA 50 provides the same information as the CA 19-9, but has no advantages over this. According to the guidelines of the European Group on Tumor Markers (EGTM), CA 19-9 should be preferred.
literature
- KS Goonetilleke, AK Siriwardena: Systematic review of carbohydrate antigen (CA 19-9) as a biochemical marker in the diagnosis of pancreatic cancer. In: European Journal of Surgical Oncology . Volume 33, Number 3, April 2007, pp. 266-270, ISSN 0748-7983 . doi: 10.1016 / j.ejso.2006.10.004 . PMID 17097848 . (Review).
Individual evidence
- ^ Gastrointestinal Cancer , European Group on Tumor Markers 2016. Retrieved January 28, 2017.
