CA 19.9

Immunohistochemical expression

This is a monosialoganglioside related to the Lewis A blood group antigen.  It is positive in most gastrointestinal and pancreaticobiliary carcinomas and less frequently in adenocarcinomas of other sites1. In the 10% of the population that is Lewis-A negative, Ca 19.9 is absent and therefore cannot be applied as a tumour marker.

Ca19.9 can be detected in fetal epithelia of the stomach, small intestine, colon, liver and pancreas. It is present in very low concentrations in adult gastrointestinal and lung tissues. It is present at high concentrations in mucin in saliva, seminal fluid, gastric and duodenal secretions, amniotic fluid, urine, bile, pancreatic secretions and ovarian cyst fluid.

It is expressed by adenocarcinomas at a wide range of sites:

Diagnostic utility

Ca19.9 is used as a serum marker with a relative specificity for tumours of the pancreas and gastrointestinal tract. Differentiation of mesothelioma from adenocarcinoma. Low sensitivity for adenocarcinoma means that it is not of general use. However, its frequent positivity in serous carcinomas of the ovary and peritoneum makes it useful in differentiating these tumours from epithelioid mesotheliomas of the peritoneum8,9.

References

1PA Fetsch et al. Utility of the antibodies CA 19-9, HBME-1, and thrombomodulin in the diagnosis of malignant mesothelioma and adenocarcinoma in cytology. Cancer 1998;84:101-8.

2Bateman, A. C., R. K. al-Talib, et al. (1997). "Immunohistochemical phenotype of malignant mesothelioma: predictive value of CA125 and HBME-1 expression." Histopathology 30(1): 49-56.

3Chenard-Neu, M. P., J. P. Bellocq, et al. (1990). "[Malignant mesothelioma of the pleura. Analysis of its immunohistochemical aspects]." Ann Pathol 10(1): 20-7.

4Ordonez, N. G. (1989). "The immunohistochemical diagnosis of mesothelioma. Differentiation of mesothelioma and lung adenocarcinoma." Am J Surg Pathol 13(4): 276-91.

5Ohshio, G., K. Yamaki, et al. (1995). "Distribution of the carbohydrate antigens, DU-PAN-2 and CA19-9, in tumors of the lung." Tumori 81(1): 67-73.

6Chenard-Neu, M. P., A. Kabou, et al. (1998). "[Immunohistochemistry in the differential diagnosis of mesothelioma and adenocarcinoma. Evaluation of 5 new antibodies and 6 traditional antibodies]." Ann Pathol 18(6): 460-5.

7Ordonez, N. G. (2003). "The immunohistochemical diagnosis of mesothelioma: a comparative study of epithelioid mesothelioma and lung adenocarcinoma." Am J Surg Pathol 27(8): 1031-51.

8Ordonez, N. G. (1998). "Role of immunohistochemistry in distinguishing epithelial peritoneal mesotheliomas from peritoneal and ovarian serous carcinomas." Am J Surg Pathol 22(10): 1203-14.

9Ordonez, N. G., R. S. Freedman, et al. (1987). "Lewis and related tumor-associated determinants on ovarian carcinoma." Gynecol Oncol 26(1): 1-10.

10Kaufmann, O., T. Deidesheimer, et al. (1996). "Immunohistochemical differentiation of metastatic breast carcinomas from metastatic adenocarcinomas of other common primary sites." Histopathology 29(3): 233-40.

Encabo G,Ruibal A Seric CA 19.9 levels in patients with non tumoral pathologies. Our experience in 892 cases. Bull Cancer 1986; 73:256-9

Tabuchi Y, Deguchi H, Imanishi K, et al. Immunohistochemical studies on the main entrance-route of CA19-9 into the peripheral venous blood of gastric cancer patients. Correlation with CA19-9 levels in peripheral and portal blood. Cancer 1990; 66:1529-33

This page last revised 25.9.2004.

©SMUHT/PW Bishop