Tests for blood in the stool for colorectal cancer screening are reliable
In addition to colonoscopy, immunological tests for blood in the stool are also available to diagnose colon cancer. Scientists at the German Cancer Research Center (DKFZ) have now compared several of these tests and found that they all give good results.
Early detection saves lives
The chances of recovery from colorectal cancer strongly depend on how early the cancer and its precursors are discovered. In Germany, legally insured persons aged 55 and over are entitled to colonoscopy for the early detection of this type of cancer. In addition to this examination, new immunological tests for blood in the stool have been used for diagnosis since this year. Scientists from the German Cancer Research Center (DKFZ) have now compared nine of these tests. They found that everyone gave good results.
Immunological tests examined
Colon cancer screening has become easier and more reliable this year. Immunological tests detect whether the blood pigment hemoglobin is in the stool. This serves as an indication of whether a patient has colon cancer or a pre-colon cancer.
The fact that the immunological tests have replaced the less specific HämOccult test is largely due to the work of Hermann Brenner from the DKFZ, the institute wrote in a message.
There are currently numerous different immunological tests on the market.
"Until now it was unclear whether and to what extent there are differences between the tests offered," says epidemiologist Brenner. That is why he and his employees have subjected nine tests to a direct comparison.
Tests discover the vast majority of all colorectal cancers
The result: All nine tests discover the vast majority of all colorectal cancer diseases and also many colorectal cancer precursors. If you follow the manufacturer's instructions as to the value from which a test can be rated positive, then the frequencies of positive results differ greatly.
However, when the scientists adjusted the threshold values during the evaluation, all tests gave very similar results.
"In this work, we are providing a direct comparison of the diagnostic value of a large number of quantitative tests in the same, large group of study participants for the first time and worldwide unique," said Brenner.
From these numbers, nationwide recommendations for the threshold values of individual tests could be derived.
Lower-threshold screening examination
"With this work, Brenner and colleagues give very specific recommendations on how to further improve the early detection of colorectal cancer," emphasized Michael Baumann, CEO of the DKFZ.
"It is important to offer people a lower-threshold screening examination in addition to the rather complex colonoscopy, which is still the gold standard in colorectal cancer screening."
Five of the nine tests require laboratory analysis. The remaining four tests can be carried out and evaluated directly in the general practitioner and urological practice.
Even the test, which is evaluated using a smartphone app, delivered reliable results - at least when it was carried out by trained personnel.
The researchers published their results in the journal "Gastroenteroolgy".
Third most common cancer worldwide
Colon cancer is the third most common cancer worldwide, according to the DKFZ. Every year, around 1.4 million people fall ill and 700,000 die. The same applies to colorectal cancer: the sooner you discover it, the better. Early detection can save lives.
Colonoscopy is considered the safest method for the discovery of colon cancer and its preliminary stages. But when should you have a colonoscopy? The examination is recommended if colon cancer has already occurred in the family.
In addition, all health insured persons in Germany who are legally insured from the age of 55 are entitled to a colonoscopy.
According to experts, however, it would make sense to aim for a new age limit and to recommend the study from 50 years.
Unfortunately, the test procedure is complex and many patients shy away from it. Only 20 to 30 percent of the beneficiaries take part. (ad)