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maintrac – Monitoring tumor activity from peripheral blood


Maintrac testing allows the enumeration of circulating epithelial tumor cells.

The cells from solid tumors circulating in blood (CETC) determine the risk of blood-borne metastases and hence the patient’s course of disease. Therefore, it is crucial to monitor the response of these cells for tailoring  systemic therapies,.

This is why we have developed maintrac. It is based on a simple blood sample in an EDTA standard blood tube. Other bodily fluids can also be tested. The method quantifies the circulating epithelial tumor cells (CETC) nondissipative, is highly reproducible, successfully audited and accredited, repeatedly validated for Europe according to DIN EN ISO 15 189 and published in high-impact journals worldwide.
With maintrac, the response to different therapeutic measures can be checked since the dynamics of the cell numbers correlates highly significantly with tumor growth and the development of metastases.
Tumors consist of heterogeneous cell populations. Chemotherapies, therefore, may not be effective on all tumor cells. The likelihood to develop metastasis increases significantly as a result of rising cell numbers which the tumor releases into the patient’s blood.,. That is why it is important to identify, quantify and characterize the patient’s tumor cells for tailoring therapy..

Three advantages for patients

  1. control of the success of customized adjuvant chemotherapy:
    Patients whose circulating epithelial blood cells are completely eliminated or considerably reduced have a reduced risk of suffering relapse.
  2. Customization of the hormone blockade:
    As long as the number of cells in the blood does not rise during hormone blockade, maybe even slowly decreases, the risk of relapses is reduced. The proliferative activity of circulating tumor cells depends on the number of their hormone receptors. With hormone receptor blockers, these receptors are blocked, thus preventing the growth of cells, for example with tamoxifen. The ability of trastuzumab to block cell growth sometimes only develops during the course of treatment.
  3. Customized and targeted therapy even in the  metastastatic situation:
    If treatment alternatives are available which had shown no statistical inferiority, we recommend to prefer those drugs that can be shown to be active to the patient’s tumor cells.

methodological approach

Tumor, Krebs, maintrac , zirkulierende Tumorzelle

The epithelial antigen EpCAM is expressed on cells of epithelial origin, such as cells from solid tumors, an antigen, that is not usually found on blood cells. This antigen can be stained with a green fluorescent antibody, in addition, blood cells are stained against with  an anti-CD45-antibody. The living EpCAM positive cells are detected and enumerated microscopically. This is possible with an additional dead / live staining dye propidium iodide. Thus, all cells into which the dye can enter nonspecificly due to a permeable membrane, are excluded. EpCAM staines all epithelial cells. Also normal epithelial cells are detected. If such cells are present. In the context of a tumor it is most likely, that the epithelial cells are tumor cells.

appearance of tumor cells

Tumor, Tumorzellen, Krebs, KrebszellenThe signal strength of the EpCAM signal on the cells has a high range of variation. Using maintrac, also cells with a very low EpCAM expression can be detected, since these might be the most important for the metastases. (EMT epithelial-mesenchymal transition)


Tumor, Krebs, Tumoraktivität, Krebsaktivität maintrac

Repeated measurments provide highly comparable results. In the example shown, three parallel samples of the same patient show almost identical results that remain constant over time.


zirkulierende Tumor zelle, Tumorzellen, Krebs, TumorDuplicate assays for more than 80 patients showed an excellent correlation.


clinical relevance

Tumor, Krebs, Tumoraktivität, KrebsaktivitätPatients with increasing cell counts during therapy are at higher risk of relapse (red Kaplan-Meier curve) than patients with decreasing  cell numbers. (green Kaplan-Meier curve).
This allows a timely change in therapy.