Specialist information

Circulating tumor cells (CTCs) in oncology

Circulating tumor cells (CTCs) are single cancer cells that, under certain conditions, are detectable in the bloodstream of cancer patients. Clinical studies support the thesis that these cells detached from the primary tumor can systematically spred trough the blood and lyphatic system in the body of cancer patients.

As aggressive cells of the original tumor tissue, some of them have the potential to develop into metastases..

 

Schematic representation of metastasis

The importance of CTCs in understanding the prognosis of cancer patients, both in the course of disease and in therapy, is steadily increasing. Molecular changes in the CTCs compared to the cells of the primary tumor can be analyzed and the results allow the physician to track the progress of therapy.

GILUPI CellCollector® vs. competitive systems

Advantages compared to competing systems

 

Clinical significance

CTCs and their importance for targeted therapies

The possibilities of treating cancer patients with individualized, targeted therapies (in contrast to chemotherapy with cytostatic drugs) have improved enormously in recent years. The knowledge of the molecular properties of cancer cells is an indispensable prerequisite for the effective use of these so-called targeted therapies (targeted therapy).

Application examples:

  • Detection of somatic mutations in CTCs

 

Die Analyse von Mutationen im EGFR- und KRAS-Gen liefert Informationen über die Reaktion eines Patienten auf gezielte Therapien (z. B. mit Iressa® oder Tarceva®). Ein routinemäßiges Testen von CTCs während der Behandlung kann Informationen hinsichtlich der Wirksamkeit der angewandten Therapie liefern

Publikation

  • Detection of androgen receptor splice variant 7 (AR-V7)

 

AR-V7 ist eine Variante des Androgen- Rezeptors, die unabhängig von der Hormonstimulation ein Wachstumssignal an die Zelle übermittelt.

Die Expression von AR-V7 führt zu einer Resistenz gegenüber Hormonentzugstherapien (z.B. mit Zytiga® und Xtandi®) bei der Behandlung des Prostatakarzinoms. Der Nachweis der AR-V7 Expression kann ausschließlich auf Protein- bzw. RNA-Ebene erfolgen. Somit ist die Verwendung von ctDNA für diese Diagnostik nicht möglich.

Publikation

 

  • Quantitative CTC detection by immunofluorescent staining

     

Diagnostic immunofluorescence microscopy is an established method for the detection and localization of cellular proteins. For this purpose, specific fluorescently labeled antibodies are used which bind to target proteins and allow their visualization.

CTCs are identified by staining the keratins as well as the nucleus. In order to exclude blood cells, a negative selection by staining on CD45 (marker for blood cells) is made. The immunofluorescence analysis is successfully used by GILUPI for the quantitative detection of CTCs.