What does sensitivity mean? What does specificity mean? 



Sensitivity: A measurement of the proportion of individuals with the disease who are correctly identified by the test. A sensitivity of 90 % means, for example, that out of 100 patients who definitely have the disease 90 are correctly identified. 


Specificity: A measurement of the proportion of individuals without the disease who are correctly identified as being disease-free. A specificity of 90 % means, for example, that out of 100 healthy individuals 10 are falsely diagnosed with the disease.

How is the sensitivity and specificity of the Septin9 test compared to other screening tests?

The Septin9 test is characterized by a sensitivity of 70 % for all cancer stages and a specificity of 90 %. These characteristics are comparable with immunological stool tests that show (depending on the test) a sensitivity of ~65 % with a specificity of ~95 %. Colonoscopy identifies more colorectal cancer cases with a sensitivity of 97 % at a specificity of 98 %. The chemical stool test detects about one third of all cases with a sensitivity of about 40 % and a specificity of 97,7 %.

What is the sensitivity for early stages?

In stage I cancer, the sensitivity of the Septin9 test is about 50 % and in stage II the sensitivity is about 80 %.

Does methylation measured in the Septin9 test only appear in colorectal cancer?

During the development of the test we found that compared to healthy intestinal tissue or blood plasma almost all tumors of the colon carry the ^mSEPT9 biomarker. Therefore the marker is suitable for the detection in blood. The specific methylation pattern also exists in other diseases or inflammatory processes but usually cannot be detected with the Septin9 test. False positive results can occur if the blood sample was not correctly stored before the analysis resulting in lysis of lymphocytes and release of excessive DNA into the sample which can falsify the result.

What makes the test better than others?

As the Septin9 test can be executed during a regular check up at the doctor’s office, it will probably make it easier for patients to participate in colorectal cancer screening. The sampling can be standardized and the test provides reliable results.

Other tests require more time and effort from the patients in their execution. Furthermore the sampling cannot be controlled and application errors can occur.

How has the  effectiveness of the test been proven? 

The correlation between Septin9 and the presence of colorectal cancer has been proven in several case control studies with approx. 4.000 individuals. The sensitivity of the test is at ~70 % with a specificity of ~90 %. Like a fecal occult blood test, the Septin9 test identifies patients who have an increased risk of having colorectal cancer. The test is not meant to establish a final diagnosis or replace a colonoscopy. Furthermore, the Septin9 test was evaluated in a large prospective study to determine its performance in the target screening population. The results show that the Septin9 test meets the requirements for use in a real screening population and therefore offers an attractive alternative to current tests for colorectal cancer early detection.

What does the Septin9 test cost?

The Septin9 test is a new technology. To ensure the quality and safety of the detection method, extended research and scientific studies were conducted. Analysis and evaluation of the blood samples in the laboratory incur costs involving high quality equipment and skilled personnel. The basis for the test in the laboratory is 10 ml blood out of which 4 ml blood plasma is extracted. The next step is DNA isolation. Afterwards, the plasma DNA is treated with sodium bisulfate for bisulfite conversion. The DNA methylation information is preserved and is transferred to sequence information for the subsequent molecular analysis. Analysis and detection by duplex real-time PCR follows. The costs (e. g. ~150-160 € in Germany) for each of these activities flow into the pricing for the Septin9 test.