Medical providers will order the CA 19-9 blood test to use as a tumor marker. It is not a sensitive enough blood test to be able to use it as a screening tool to diagnose a malignancy, but it can help to differentiate whether there is a cancer present or an inflammation or infection that is causing bothersome symptoms. It is also ordered to monitor how an individual is responding to medical treatments and can be used to watch for a relapse of a cancer.
It is an effective blood test only when a tumor is creating enough of this marker, so it is typically ordered with a series of other tests that measure the functioning of the liver and pancreas. About 6 in 10 people with bile duct cancer will also have elevated levels of CA 19-9, so it may also be ordered if this condition is suspected. CA 19-9 levels may also rise if there is a bile duct obstruction.
When Should I See a Doctor?
Unfortunately many of the conditions that the CA 19-9 blood test is able to detect have a cause that is currently unknown to medical science. There are certain risk factors that may indicate a higher than normal risk for developing pancreatic cancer. These include being in the 50+ age demographic, being male, having diabetes, or having a family history of pancreatic or similar cancers. Individuals who have be exposed to certain dyes and chemicals also have an increased risk of cancer development.
About 80% of people who do have pancreatic cancer will experience some level of abdominal pain. This is due to the tumor growing. When the liver is affected, there may be pale-colored stools and dark urine as well. Nausea, bloating, and frequent diarrhea also occur. This is why this cancer is so difficult to detect. This cancer typically grows silently and without pain until it is ready to spread.
What Do My Test Results Mean?
Most people will have low levels of CA 19-9 in their blood. There are numerous medical conditions which may affect the liver or pancreas that can temporarily cause levels to rise. Low level amounts are generally considered a normal reading if there are no signs or symptoms of cancer or organ distress. It is useful as a tumor marker because the tumors will shed CA 19-9 over the regular course of their life.
CA 19-9 is not a cancer causing agent.
When there are moderately high levels of CA 19-9 discovered on the blood test, then this may indicate the possibility of a malignancy. Although 95% of pancreatic cancers will create this type of result, certain other cancers and diseases can also simulate the results. That’s why this one test alone cannot be used as a screening tool for cancer.
Most people who have elevated levels of CA 19-9 are usually at an advanced stage of their cancer because pancreatic cancer has very few symptoms that register as significant. It is not unusual for someone to not experience any ill effects until the cancer begins to spread into different regions of the body.
If CA 19-9 Is Detected, Why Isn’t It Used Regularly?
If someone is not exhibiting the signs or symptoms of cancer or a bile duct obstruction, then the test results on the CA 19-9 blood test are not considered reliable. There are many false positives and false negatives that have been associated with regular testing. A CT scan is often a more reliable method of determining if there is cancer present. An MRI or an ultrasound may also be recommended in lieu or in combination with this blood test.
Although it is commonly used for cancer or tumor monitoring, a positive CA 19-9 blood test can also be seen in liver disease and cystic fibrosis. Lung and colorectal cancers may also have a positive test result.
The diagnosis of pancreatic cancer can be relatively frightening. Survival rates have been improving over the years, but the 1 year survival rate for all pancreatic cancers after diagnosis is just 20%. The five year survival rate is currently just 6%. If you have a family history of cancer, especially within your direct family and pancreatic cancer is involved, then any time the signs or symptoms mentioned here are experienced may be a good time to have a conversation with a medical provider about this blood test.
The CA 19-9 blood test results explained here provide generalized information except in specific circumstances. Listen to your body, seek help if needed, and this test may provide the information needed to begin an early intervention treatment plan.