The Septin9 test is a diagnostic procedure for the early detection of colorectal carcinoma (colorectal cancer). The test method is based on the use of a blood test to detect the biomarker mSEPT9. The Septin9 test increases the probability of early detection and thus offers an improved chance of cure. In contrast to a colonoscopy, no unpleasant pre-treatment of the intestine (bowel cleansing) is necessary. Also, the intake of medication is not a confounding factor, since the mSEPT9 level is not affected by the intake.
The procedure
On the basic principle of detection of the biomarker mSEPT9:
- Colorectal carcinomas (colon carcinoma; colorectal cancer) are known to arise from predominantly benign (benign) tumors, from which malignant (malignant) tumors can develop as a result of various mutations. So-called epigenetic changes, such as the occurrence of mSEPT9, are also crucial in the development process. In addition to the occurrence of mSEPT9, other biomarkers associated with the occurrence of intestinal tumors have also been discovered. VIM, RASSF2, ALX4, SFRP1, APC and TFF1 can be listed as examples. However, only the determination of mSEPT9 in blood plasma is currently of diagnostic significance.
- MSEPT9 was detected in cells from various mammals and could be recognized as an important component in the regulation of cellular processes. In particular, the biomarker can interfere with the cell’s function to initiate apoptosis (controlled cell “suicide” driven by gene expression) or to maintain phase in the cell cycle (to die or to continue living). This explains why the marker is optimal as an early warning system for the occurrence of colorectal cancer.
- Due to a defect in the control function of the marker, the cell can proliferate unhindered, so that an important criterion of tumorigenesis is fulfilled.
Material needed
- 10 ml whole blood, transport in refrigerated container at 4 °C.
Preparation of the patient
- Not necessary
Disruptive factors
- None known
Standard values
To the result
- Depending on the test result, the diagnostic approach varies. If there is a positive (pathological) finding, a colonoscopy must be performed immediately to detect and treat any neoplasia (new tissue formation) that may be present.
- If the result is negative, it is highly likely that the patient does not have colorectal cancer.Nevertheless, within two years, the test should be repeated. In particular, people over the age of 50 are considered particularly at risk, so that the Septin9 test is useful here as a preventive measure.
Indications (areas of application)
- Colorectal cancer screening (colorectal cancer screening) – The high sensitivity of the procedure (percentage of diseased patients in whom the disease is detected by the use of the test, i.e. a positive test result occurs) makes the Septin9 test an optimal additional method for the early detection of colorectal cancer. In addition to the good detection rate of a tumor, the procedure has the potential to increase the acceptance of colorectal cancer screening.
Study data on the Septin9 test
| Stage | Training study 2008 (n=269) | Test study 2008 (n=245) | CE Study 2009 (n=257) |
| % positive | % positive | % positive | |
| I | 45 | 47 | 57 |
| II | 82 | 73 | 86 |
| III | 79 | 74 | 61 |
| IV | 100 | 100 | 89 |
| I-II | 68 | 64 | 66 |
| I-III | 72 | 67 | 67 |
| All | 73 | 69 | 67 |
| Controls (specificity) | 7 (93) | 11 (89) | 12 (88) |
Additional Notes
The Septin9 test is designed to detect an increased likelihood that a patient has colorectal cancer. However, the following conditions have a significantly increased risk of disease anyway, so Septin9 testing is not indicated and colonoscopy should be performed primarily as part of colorectal cancer screening:
- Genetic burden – in the presence of colorectal cancer in the family, there is an increased risk, so regular colonoscopy is indicated.
- Familial adenomatous polyposis – pathological process in which there is mass formation of polyps (benign tumors), which, however, can often appear as malignant tumors due to mutations.
- Ulcerative colitis – belongs to the group of chronic inflammatory bowel diseases; it is characterized by inflammatory involvement of the rectum (rectum) and colon (colon). Unlike Crohn’s disease, the inflammation spreads continuously starting from the rectum, that is, from anal to oral, and is limited to the mucosa and submucosa (intestinal mucosa).
- Crohn’s disease – chronic inflammatory bowel disease; it usually progresses in relapses and can affect the entire digestive tract; characteristic is the segmental involvement of the intestinal mucosa, that is, several intestinal sections may be affected, which are separated by healthy sections.
