What are tumor markers?

I have elevated tumor markers. Does this mean I have cancer?

Tumor markers are biomarkers that can be found in the blood (most often), urine or tissues of people who have a malignant disease. There are several types of markers, and each one is related to a specific tumor or group of malignant tumors, and they are used in oncology to detect the presence and activity of the disease. Tumor markers can be produced by the tumor itself or by non-tumor cells in response to the presence of a tumor in the body. The majority of tumor markers are produced by both normal cells and tumor cells, but tumor cells produce them in greater quantities, which is why their concentration can be elevated in cancer patients. It should be noted that tm markers are not a definitive diagnostic test, and the diagnosis must always be confirmed with a biopsy.

It is important to emphasize that elevated tumor markers do not necessarily mean that a person has a malignant disease. In general, routine monitoring of tumor markers is not recommended due to their non-specificity. Namely, tumor markers can be elevated due to a number of conditions (for example, PSA can be elevated in prostatic hyperplasia, and CA19-9 in pancreatitis), and the opposite is also possible - a patient with active malignant disease may not have elevated tumor markers. However, tumor markers are a useful tool in monitoring patients, because analyzing their trend can sometimes predict a relapse of the disease or a worsening of the findings before imaging methods show it. It is certainly wisest to leave the decision to control tm markers to an experienced oncologist who will be able to assess the importance of the findings requested.

Figure 1. Tumor markers are mostly analyzed from patient blood samples. The results are usually ready the same day.

Some of the most commonly used tumor markers:

CEA (carcinoembryonic antigen) - This is a tumor marker that is normally produced in the digestive tract during fetal development, while its production stops later. Accordingly, CEA blood levels in adults are usually very low (2-4 ng/ml). CEA can be elevated in people with certain types of cancer, primarily originating from the digestive tract (colon, stomach, pancreatic cancer), but also in lung, breast and medullary thyroid cancer. It should be noted that CEA levels are usually elevated in people who smoke.

CA19-9 (carbohydrate antigen 19-9) - It is important in the diagnosis and monitoring of patients with pancreatic cancer, although it can occasionally be elevated in other tumors located in the abdomen. It is known that people with a deficiency of Lewis antigen A on red blood cells cannot produce this tumor marker. Such individuals account for about 10% of the white population, and even in the case of very large pancreatic tumors, they have very low or undetectable CA19-9 values.

PSA (prostate-specific antigen) is measured in the blood. It is a substance produced by the prostate and is in most cases elevated in patients with prostate cancer. However, PSA can also be elevated in some other benign conditions, such as infection or inflammation of the prostate and prostatic hyperplasia. Therefore, the finding of elevated PSA does not immediately mean that a person suffers from prostate cancer, but it requires further treatment.

CA125 (carcinoma antigen 125) was discovered in 1984, and was found in fetal tissue, bronchial epithelium and bronchioles of healthy individuals. It is important in the diagnosis and monitoring of ovarian cancer. It is elevated in over 80% of cases of serous ovarian carcinoma, and the values ​​usually follow the size of the tumor mass (an increase in the marker is recorded as the tumor grows). However, it can also be elevated in some benign conditions such as endometriosis and inflammation of the ovaries and fallopian tubes.

CA15-3 (carcinoma antigen 15-3) is a tumor antigen important in monitoring breast cancer. However, like other tumor markers, it is not completely specific, and can also be elevated in a large number of pathological conditions in the abdomen and in patients with lung cancer. Elevated CA 15-3 values ​​​​are not significant in detecting new cases of breast cancer. An increase in this tumor marker after treatment in a large percentage indicates the occurrence of disease recurrence long before it becomes clinically evident, and also correlates with disease progression, while a decrease indicates a partial or complete response to therapy. However, it is not suitable for early detection (screening) or diagnosis.​​

Continue reading:

Determining disease stage

Need more information about this topic? Contact us.