Introduction
“Tumour marker” has become a familiar term when it comes to cancer. Nevertheless, very few people know exactly what the term means. A tumour marker is a specific molecule that can usually be measured by a blood test and that indicates the presence of a tumour (e.g. breast cancer, colon cancer, prostate cancer). The first appearance or an increase in normal values should then indicate a particular cancer.
Tumor markers in breast cancer
The most interesting tumour marker for breast cancer is CA 15-3 (cancer antigen). Elevated levels of this protein molecule can be measured in breast and ovarian cancer. But other diseases can also lead to an increase in CA 15-3 values, such as hepatitis (inflammation of the liver), pancreatitis (inflammation of the pancreas) and various inflammatory diseases of the lung and gastrointestinal tract.
In the case of breast cancer, the level of the measured values is quite well related to the disease activity, e.g. it can be assessed whether chemotherapy is effective or not. Standard values: However, it should be mentioned here that there is a certain grey area for all tumour markers. An increased value does not automatically mean that one is suffering from a tumour disease. Elevated values can also occur with benign diseases. – CA 15-3: <28 units/ml
- CEA (carcinoembryonic antigen): <5 ng/ml
How likely am I to have breast cancer if the tumour marker is elevated?
No tumour marker is tumour-specific. Elevated concentrations are also detectable in healthy people. They are important when the early detection of a relapse or progression of a patient’s tumour offers a benefit for quality of life or life expectancy.
Pure values do not have sole significance. The overall picture of the patient is important. A grey zone of CA 15-3 applies to values between 25 – 35 IU/ml.
Above 35 IU/ml it would be suspect. The situation is similar with CEA. Values between 5-10 IU/ml are in the grey zone.
Above 35 IU/ml it has a disease value. Despite these values, it is not possible to tell a patient 100% whether he has a tumour or not. This can only be proven after further examinations with the aid of apparatus. The following topic could also be interesting for you: BRCA mutation
Are there tumor markers for bone metastases?
There are markers that provide an indication of bone metabolism. These include deoxypyridinoline, which is a very specific marker for bone resorption and thus for the activity of osteoclasts. There is also pyrodinoline, but this does not have the specificity of deoxypirodinoline.
Another marker is bone phosphatase, also called ostasis. It belongs to the alkaline phosphatase, which is contained in many metabolic pathways of the body. This marker is also significantly increased in bone resorption.
It is removed and examined, among other things, if bone metastases are suspected. In medicine, however, it is important not to rely solely on laboratory values. A more precise indication of bone metastases is provided by bone or skeletal scintigraphy. This is a procedure to show the metabolic activity of the bone. Here the patient receives a radioactively labelled substance that accumulates in particularly active areas of the bone.
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