ColoAlert – colon cancer screening test kit

07.10.2024Gotse Delchev, Plovdiv, Sofia

ColoAlert is a colon cancer screening test. This kit is used to collect stool samples from the patient.

Advantages of tumour DNA analysis

Early in the development of colorectal cancer, there are somatic – i.e. acquired during life – mutations in the genome of intestinal cells. As the cells of the intestinal mucosa are continuously removed in the stool, their DNA can be detected in the stool using PCR.

For diagnosis, the ColoAlert lab first separates human DNA from DNA from other sources, such as gut bacteria and food. It then quantifies the total amount of human DNA . In the case of tumors – but also in the case of inflammatory processes – the total amount of human DNA in the stool increases noticeably. In a next step, the laboratory tests the DNA for common KRAS and BRAF gene mutations.

KRAS gene mutation
The KRAS gene (K-RAS gene) encodes the K-Ras protein of the same name, which regulates cell growth and cell division as a molecular switch. To do this, it switches between active and inactive states. If there are mutations in the KRAS gene, the K-Ras protein is always active. This leads to uncontrolled cell division and the tumour grows uncontrollably.

About one in three tumours has a mutation in one of the RAS genes. This applies in particular to colon and exocrine pancreatic carcinomas. Because the mutations involved are somatic, ColoAlert is not a genetic test in the conventional sense.

The frequent involvement of the K-Ras protein in tumorigenesis also makes it an important therapeutic target. For example, researchers have been able to find an inhibitor that disrupts KRAS transport to the cell membrane and thus significantly reduces tumor growth. This is yet another reason why the detection of a mutation in the KRAS gene is a plus for ColoAlert colorectal cancer diagnostics.

BRAF gene mutation
The BRAF gene (B-RAF gene) encodes a special protein kinase, the serine/threonine kinase B-Raf, which also regulates an important signaling pathway for cell division and differentiation. Mutations in the BRAF gene can permanently activate the signalling pathway and thus contribute to the development of colorectal cancer, for example.

The BRAF V600 mutation, which causes fast-growing and aggressive tumours, is particularly common in tumour cells. About 8 to 10 percent of all patients with metastatic colorectal cancer are affected.

BRAF inhibitors can block the signaling pathway and thus induce apoptosis of tumor cells.

How reliable is the ColoAlert test?
Analyzing these biomarkers, ColoAlert achieves a sensitivity of 85% and a specificity of 92%. As with any diagnostic procedure, both false negative and false positive test results can occur.

What should I do in case of a positive result?
In case of a positive test result, no
therapeutic measures should be taken without prior consultation with the treating therapist.