Why tumor markers do not help detect malignant tumors

We do not like to go to the doctors, but we still worry about our health. Especially when it comes to the dangers of cancer. There is a persistent myth that a test for tumor markers helps to determine the appearance of a tumor. A negative result of the study is an occasion to relax and calm down. Why this is not so, Pavel Koposov, deputy director of the Institute of Oncology of the European Medical Center (EMC), oncologist, doctor of medical sciences, explained to Moskovskaya Pravda.

Tumor markers are proteins that are normally present in blood plasma and can indicate certain types of cancer. Their presence is one of the indicators of the possible development of a malignant tumor. However, even a high level of tumor markers in the blood does not always mean that a person has cancer.

– In some cases, these indicators may be present in various inflammatory processes and during pregnancy. Moreover, not all types of cancer can be detected using tumor markers, explains Pavel Koposov.

The expert added that, as a rule, with small tumors, you can not see any changes in the analyzes at all, and large tumors can be manifested by zero or moderate levels of tumor markers.

“For example, a patient’s blood contains the CA-125 protein, which is produced by an ovarian cancer. However, its level may be normal in patients with early stages of cancer, since it only rises in large tumors, when the disease is already advanced. In addition, the level of CA-125 can also be increased in other diseases, such as endometriosis, inflammatory processes, and the like, Pavel Koposov said.

Oncomarkers are not indicative for the detection of other types of oncology. Thus, for breast cancer, the most common tumor marker is CA 15-3, which can be elevated in patients with an aggressive form of cancer. However, according to the expert, it cannot be used to detect breast cancer. Although in the treatment of metastatic disease, this test can be a marker of the activity of the cancer process.

The same goes for the PSA test, which is used to detect prostate cancer. Its results can be increased in other diseases of the prostate, such as adenoma or inflammation.

“So it is impossible to use tumor markers as a tool for early cancer diagnosis,” the expert sums up. – For this, other studies should be carried out: CT, MRI, PET-CT, biopsy.

Therefore, as a control of your health, a test for oncomarkers practically does not make sense. But it is a useful tool for monitoring certain types of cancer during treatment.

Alena Bodrienko.

Photo by Sergey Vedyashkin / Moskva Agency