Talk:CA 19-9
From Descipher Health
CA 19-9 (Cancer antigen 19-9) A tumor marker associated with pancreatic cancer.
Once cancer is diagnosed, tumor marker levels help determine the amount of cancer present. Higher levels usually indicate more advanced cancer and a worse prognosis. The person and his or her physician use this information to choose between more or less aggressive treatments. Monitoring cancer treatment is the most common use of tumor markers. As cancer is reduced, levels decrease. Stable or increasing levels indicate the cancer is not responding to treatment. The choice of tumor marker to use for monitoring is important. Only a marker elevated before treatment can be used to monitor a person during or after treatment. Timing of the tests is also important. Each tumor marker has a unique lifespan in the blood. To monitor a treatment's success, enough time must have passed for the initial marker to be cleared from the blood. Tests done too soon may be falsely elevated because the marker produced by the untreated cancer is still present. Conclusions based on tumor marker tests are seldom based on one test result but on a series of test results, called serial measurements. A series of increasing or decreasing values is more significant than a single value. CA 19-9 helps diagnose pancreatic cancer when combined with other test results and clinical findings. After diagnosis, levels help predict the success of surgery and to monitor the course of the cancer. Not all people with pancreatic cancer have increased CA 19-9 levels. This marker is associated with a specific blood type. People with pancreatic cancer who are negative for this blood type will not have CA 19-9 in their blood. It is also increased in liver and gastrointestinal cancer and in noncancerous diseases, such as pancreatitis and jaundice. The CA 19.9 cancer antigen is a glycoprotein associated with malignant neoplasms . The CA 19.9 assay is based on the use of a monoclonal mouse 116-NS-19-9 antibody. It is measured to aid in the management of patient with malignancies . CA 19.9 antigen is most often followed in the patient with pancreatic and colon cancer. The CA 19.9 may also be elevated in stomach and hepatobiliary malignancies. Sometimes in benign inflammatory disease of pancreas, gallbladder and liver CA 19.9 may also be elevated. The CA 19.9 assay level decreases after therapy and increases in cases of relapse, residual disease and metastasis. The CA 19.9 assay is used as an additional test for the prognosis and monitoring of therapy of patients with diagnosed malignant tumours. A decrease in the CA 19.9 assay level can indicate a positive response to therapy and therefore good prognosis. A constant increase of the CA 19.9 assay value often reflects evolution of the tumour and a poor response to therapy.
