Study New immunological stool test Part of colorectal cancer screening

Amendment to the Cancer Screening Directive
An early diagnosis brings with colon cancer crucial advantages of the treatment options. The inclusion of the immunological stool test in the cancer screening directive will further improve the early detection of colorectal cancer. The Federal Joint Committee (G-BA) has determined that quantitative immunological tests (iFOBT) should replace the currently used guaiac-based test (gFOBT), according to the Communication of the Cancer Information Service of the German Cancer Research Center (DKFZ).

New tests promise better results
According to the Cancer Information Service, numerous studies have "demonstrated that new tests can detect non-visible blood in stool with greater sensitivity and specificity." Although the guaiac-based test used so far has been shown to reduce the rate of colon cancer death, the immunological Tests promise even better results according to the expert. Therefore, the G-BA has decided to adapt the guidelines for early detection of cancer.

The decision is now to be examined by the Federal Ministry of Health (BMG) and, if approved, the changes could take effect as early as October after publication in the Federal Gazette.

The immunological stool test is planned as part of colorectal cancer screening in the future. (Image: esben468635 / fotolia.com)

Detailed regulations decided
The decision of the G-BA does not only provide for inclusion of the immunological tests in the guidelines for the early detection of cancer, but also regulates the details related to the implementation of the new test procedure, the DKFZ reports. Thus, it has to be determined which criteria quantitative iFOBT have to meet, who belongs to the circle of participating physicians and how the evaluation of the tests and the documentation should look like. According to the DKFZ, the text of the decision and the reasons for the decision will be published shortly on the websites of the G-BA.

Reimbursement by the health insurance would be possible in the future
If the BMG agrees and the decision comes into force, the costs for a quantitative immunological stool test may be reimbursed by the statutory health insurances (GKV) in the future, whereas up to now it has to be paid for by the patients as individual health management (IGeL). In the meantime, "a number of randomized studies have been published comparing different immunological tests directly with a guaiac test. These comparative studies have shown that immunological tests can detect colon cancer and its precursors even more frequently than the guaiac test, "report the experts of the DKFZ. The sensitivity (sensitivity) of the tests is higher, which, however, partly at the expense of the target security (specificity) go.

Differences between quantitative and qualitative immunological stool tests
The immunological stool tests are currently offered in Germany in two variants, but according to the information provided by the Cancer Information Service, there are considerable differences in terms of sensitivity and, in particular, specificity. "Many of the tests have too high a rate of false-positive test results (low specificity) for early detection examinations and are therefore not suitable for screening," explain the DKFZ experts. This applies in particular to the qualitative immunological stool tests, because with their fixed sensitivity threshold only a yes or no statement is made.

Improved test characteristics, according to the Cancer Information Service, provide quantitative immunological stool tests. Here, the sensitivity threshold is not fixed, but can be adapted to the respective requirements. Crucial for the use of the quantitative tests in colorectal cancer screening is that the sensitivity threshold is chosen as best as possible. Here the highest possible sensitivity with 90% specificity at the same time would be optimal according to the experts. However, the colonoscopy, which is recommended as the gold standard for the early detection of colorectal cancer from the age of 55, can not be replaced by the immunological stool tests, the Cancer Information Service concludes. (Fp)