What is CA 125?
CA 125 or (cancer antigen 125 or carbohydrate antigen 125) is also known as MUC16 or mucin 16. MUC16 is part of the mucin family glycoproteins and can detect ovarian cancer by performing a CA 125 blood test. CA 125 antigens are proteins which are present on the surface of ovarian cancer cells which show their presence in the blood stream after release from the cell. The test is to measure antigen count in the blood stream. Other conditions that raise the levels of CA 125 antigens are cirrhosis of the liver, types of cancer, endometriosis and pelvic inflammation. Change in blood levels can also be during menstruation and pregnancy.
Conducting the CA 125 blood test
Laboratory procedure for CA 125 is similar to all other tests. Collection of blood sample is from the vein of the arm, into a syringe or a vial. Before that one has to tie an elastic band around the arm, as this accumulated blood in the region. After collection, cotton or gauze pads cover the region. There are no risks associated with the condition, except for little bruise and pain for few hours. All this feels like an easy pin prick. The medicines that treat cancer and surgery of the belly affect the test.
Why the Test is Performed
A patient who is under ovarian cancer treatment undergoes periodical testing. This is because the CA 125 test is a marker for the re occurrence of cancer and the extent of success from the ongoing treatment.
Other symptoms that raise the levels of CA 125 antigens are:
- cirrhosis of the liver
- types of cancer
- pelvic inflammation
Performing the CA 125 Blood Test
Performing a series of tests gives comprehension on the rate of growth. It is highly essential to conduct similar assay through out the series. The test requires minimum volume of 0.6 ml from the patient. One requires 0.5 ml of the 1.6 ml in the collection for processing. The blood serum undergoes an automated immunoassay whose results are not markers of the disease. While this is one of the methods, there are a number of other methods to detect the presence of the protein in the blood.
Elevated CA 125 Levels
Elevated CA 125 Levels
Levels of CA 125 in the blood stream are detrimental of the origin of cancer. Very high levels signify that the release is from the ovarian surface. This does not mean that other organ cancers do not exhibit these antigens, they do show CA-125 antigens, but at lower levels. Depending on the levels, the spread rate during metastasis cancer deciphers.
What is the normal range for CA 125?
Test results of 35 units per ml come under elevation scores, which is the normal range to be in. The test classifies as true and false. The former identifies the patient to be suffering from ovarian cancer and the later declares an absence.
Differences between CA 125 Blood Tests
There are two types of CA 125 tests. One is the first generation and the other is the second generation. The second show variations in results from day to day while the first display consistently. Another difference is that the second tend to show slightly higher results.
Effectiveness of the CA 125 Blood Test
The test detects only 50% of stage 1 patients. Chances of detection increase to 80% in the stage 2, 3, and 4. Coupling the test with the complete blood count test (CBC) gives a clear understanding as rise in the blood stream can also be due to other causes. Another factor is that the test does not differentiate between cancerous and non cancerous lumps. Thus, deduction needs performing other tests too.