Septin9

Frequently asked questions about the Septin9 test

What is the Septin9 test?
The Septin9 test is a CE-marked test which detects the presence of methylated DNA of the Septin9 gene, a colon cancer-specific DNA change in blood plasma. The presence of circulating, methylated, cell-free Septin9 DNA (mSEPT9) in the blood plasma correlates strongly with the presence of colon cancer.

How does this test help me in caring for my patients?
It is assumed that this blood-based test will be accepted by many patients who have previously refused conventional screening examinations such as a colonoscopy or faecal occult blood tests (FOBT). The Septin9 test may be an attractive alternative screening procedure for these patients. The more people who undergo this test, the greater the chance that the overall rate of deaths from colon cancer will be reduced.

Test performance

What studies have been carried out to confirm the clinical effectiveness of the test?
The mSEPT9 biomarker was successfully tested in 8 different case-control studies involving more than 3,300 participants and in which it was possible to demonstrate repeatedly that the marker is a reliable indicator of the presence of colon cancer. The results of two clinical case-control studies in 2008 have been published in the journal Clinical Chemistry (Ed. 55/7, 1 July 2009) under the title „Circulating Methylated Septin9 DNA in Plasma Is a Biomarker for Colorectal Cancer”. The Septin9 test has consistently identified about 70 % of cases of cancer in training and testing studies, with a specificity of 90 %. This makes the Septin9 test much more sensitive than the widely used guaiac FOBT test (= „blood in stool test”).

Eligible patients

For which patients is the Septin9 test suitable?
The test is suitable for people with an average risk of colon cancer who want to be tested for colon cancer even though they have no symptoms of it. It can be used as an alternative way to test patients who are supposed to follow the recommended regular colon cancer screening guidelines, but who refuse to undergo the methods offered that are recommended in the above-mentioned guidelines, e.g. colonoscopy and FOBT (faecal occult blood test). Colon cancer screening is recommended for people from the age of 50 and up, but it is quite possible for younger people to have the test as well. It is not claimed that this test can replace a colonoscopy, but it offers an alternative first step in the early detection of colon cancer.

Patients who have tested positive should by all means undergo a colonoscopy for clarification purposes.

Should certain patients be excluded from this test?

Patients with a medical history of bowel cancer, familial adenomatous polyposis and significant, nonpolypoid cancer of the large intestine have an increased risk of developing colon cancer. There are special screening guidelines for these patients.

Patients with inflammatory bowel diseases, such as ulcerative colitis or Crohn’s disease, are advised to make use of the special screening programmes available.

How should the patient prepare for the test?
No preparation is necessary before undergoing the test. Compared to the stool tests, there are no restrictions for diet or with respect to taking medications or vitamin preparations.

Test results

Does a positive test result mean that my patient has colon cancer?
A positive test result means that there is an increased likelihood that the patient has colon cancer. Just as with many other diagnostic tests, there is also the possibility of false positive results. The Septin9 test has a specificity of 90 %, meaning that there are false positive results 10 % of the time. To confirm the diagnosis, these patients should by all means undergo a colonoscopy.

Does a negative test result mean that my patient does not have colon cancer?
Just as with many other diagnostic tests, there is the possibility of false negative results. This is especially true in the early stages of polyposis and adenoma. Colon cancer develops very slowly over a period of 10-15 years. In line with the guidelines, we therefore recommend regularly repeating the test when there are negative results. The interval should be every 1 to 2 years in order to detect developing cancer at a very early stage during retesting.

If a patient undergoes the Septin9 test, does this mean that he/she does not need a colonoscopy?
Just like a stool test, the Septin9 test identifies patients who have an increased risk and probability of having colon cancer. The test is not intended to make a definitive diagnosis or to replace a colonoscopy.

What clinical tests may result from the Septin9 test result?
Patients with a positive test result should defnitely undergo a colonoscopy in order to confirm the result of the test. In the case of patients with a negative Septin9 test result, regular repetition of the Septin9 test at an interval of 1 to 2 years is advisable (in line with the guidelines).

What do you tell the patient if the Septin9 test was positive, but the subsequent colonoscopy produces no abnormal findings?
Even though the mSEPT9 has been specifically developed as a biomarker test for colon cancer, and a positive test result means a high probability that there is colon cancer, research has shown that methylated SEPT9 also occurs biologically in healthy normal people whose colonoscopy results do not show any abnormalities, i.e. these cases do not constitute technical measurement errors. Possible causes include cancers in other organs or inflammatory diseases of the gastrointestinal tract. There currently is no data available on the course of the illness in such persons with respect to colon cancer (prognosis) or the probability of false negative results from the colonoscopy.

According to the study results, the following patients had positive Septin9 results:

  • „Positive test results were observed in some patients with the following diseases: bladder cancer, lung cancer, chronic inflammatory bowel disease, individual cases with systemic lupus erythematosus, chronic heart disease, respiratory diseases, rheumatoid arthritis, non-rheumatoid arthritis, inflammation of the renal pelvis (pyelonephritis), gall bladder inflammation (cholecystitis)”.

According to the S3 guidelines, colonoscopy is the method of choice for the early detection of colon cancer. This means that, following a negative colonoscopy result, no further measures for the early detection of colon cancer are indicated.

A follow-up colonoscopy is recommended after 10 years. Naturally, it is at the discretion of the attending physician to initiate suitable diagnostic measures if suspicions of colon cancer persist.

How often should a patient undergo a Septin9 test?
Like all screening tests, the Septin9 test is not a one-off test. It should be repeated at regular intervals in order to ensure maximum effectiveness and certainty. This is because a patient’s current test results do not have any predictive value concerning his/her future risk of developing colon cancer.

Submitting a patient sample for the Septin9 test

What is needed for submitting a sample for the Septin9 test?
The test requires a 9 ml CPDA blood sample from your patient, which can be sent by post to the laboratory at room temperature. The sample should arrive at the laboratory within 48 hours of being taken. When using a 9 ml EDTA tube, the blood sample must be transported to the laboratory within 24 hours at a temperature of 2-8 °C. This is usually done using the laboratory’s courier service. At the laboratory, the plasma is prepared and the Septin9 test carried out.

For more information about preanalytics, please refer to the instructions for taking blood samples.

Will the costs of the test be reimbursed by health insurance?
The Septin9 test is only offered to people who pay out-of-pocket and for privately insured patients.

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