Circulating Tumor cells (CCCs)
Today, the topic of our conversation is circulating tumor cells (CCCs).
Lyudmila Grivtsova, Head of the Department of Clinical Immunology at the A.F. Tsyba MRSC, a branch of the NMRRC of the Ministry of Health of Russia, will help us to understand this difficult topic.
What is it? Why do they need to be investigated? What benefits can this bring to the patient?
Modern oncological science and practice have stepped far and now we are able to achieve stable and long-lasting remissions in some oncological patients. But, unfortunately, in some of our patients, the disease returns, metastases appear. Why is this happening?
-The tumor is able to spread its cells throughout the body, using such transport arteries as blood and lymph, – explains Lyudmila Yurievna. – With the blood flow, individual tumor cells (and these are tsoki) or complexes of tumor cells (micrometastases) spread throughout the body, lingering in some organs and tissues, primarily in the bone marrow. This is not yet metastasis, but an intermediate stage of its formation. In the bone marrow, lymph nodes or liver, such single tumor cells can remain dormant for a long time, but under certain conditions “wake up” and give rise to metastases. The disease breaks out again. Thus, TSOKI is one of the important components of the metastatic process, its intermediate stage.
It is not easy for these cells to live in the blood, because each of them must pass a certain number of barriers in those places where they will be able to metastasize. Not all of them will survive – blood is a very aggressive environment that works against them. However, some CSCs have a strong potential for survival, they are the ones that give rise to new metastases.
-Therefore, we must identify, evaluate and monitor the dynamics of the quantitative and qualitative composition of circulating tumor cells in the blood of an oncological patient. The prognostic significance of this small cell population has now been absolutely precisely determined and certain threshold levels have been identified. For example, in breast and prostate cancer, if five (5) or more such cells are detected in the peripheral blood of a patient, we can talk about certain risks. Unfortunately, the likelihood of a relapse of the disease in this case is high, – says Lyudmila Yurievna, – This means that such a patient requires special attention and enhanced monitoring, possibly a revision of the treatment plan or more frequent regular examinations.
They can tell not only about an unfavorable prognosis, but also help the doctor prescribe competent targeted therapy.
These cells differ in their biological characteristics, and if doctors find expression of certain receptors on them, to which there are targeted drugs, this will expand the possibilities of drug therapy for the patient. Such a personalized approach is a new level of assistance to people who are struggling with cancer.
-Technically, the moment of evaluation of CSCs is very difficult due to their small number (only 1 cell per millions of blood cells) and for this it is necessary to apply special technologies – they cannot be distinguished by standard microscopy methods. In our Center, we have adapted the flow cytometry method to assess the quantity and quality of circulating tumor cells. In order to analyze all the cells obtained from 8 milliliters of blood, it takes about 7 hours, – says Lyudmila Yurievna.
Then laboratory doctors start working, who study all the information received and evaluate the result.
If, according to the results of the study, the number of TSCs exceeds the permissible values, but there are no clinical manifestations, the analysis must be repeated after 3 months. Each tumor has a sensitivity to metastasis to certain organs, and the oncologist is well aware of this.
-When is it necessary to do this analysis for the first time?
-As soon as you have minimal signs of a tumor, it makes sense to conduct a study.
-Is it possible to somehow deal with a large number of these cells in the blood if there are no signs of metastasis?
-We think it’s possible! We recommend certain immunotherapeutic approaches to such patients.
You can ask all your questions and make an appointment by calling the contact center at 8 484 399 31 30
Press Service of the NMRRC of the Ministry of Health of Russia