Colorectal cancer screening All tested immunological tests give good results

Tests for blood in the stool for colorectal cancer screening are reliable

In addition to colonoscopy, immunological tests for blood in the stool are available to diagnose colorectal cancer. Scientists from the German Cancer Research Center (DKFZ) have now compared several of these tests and found that all give good results.

Early detection saves lives

The chances of a cure for colorectal cancer depend heavily on how early the cancer and its precursors are discovered. In Germany, those with statutory health insurance from the age of 55 have the right to colonoscopy for the early detection of this type of cancer. In addition to this study, since this year, new immunological tests for blood in the stool for diagnosis are used. Scientists from the German Cancer Research Center (DKFZ) have now compared nine of these tests. They realized that all deliver good results.

For several months, new immunological tests for blood in the stool have been used for colorectal cancer screening. An investigation showed that these tests are reliable. (Image: Dan Race / fotolia.com)

Immunological tests examined

Colorectal cancer screening has become easier and more reliable this year. Immunological tests detect if the blood pigment hemoglobin is in the stool. This serves as an indicator of whether a patient is suffering from colon cancer or a colorectal cancer precursor.

The fact that the immunological tests have replaced the less specific HemOccult test is largely due to the work of Hermann Brenner from the DKFZ, the institute writes in a statement.

There are currently many different immunological tests on the market.

"So far, it was unclear whether and to what extent there are differences between the tests offered," says epidemiologist Brenner. That's why, together with his employees, he has made nine tests a direct comparison.

Tests detect the vast majority of colorectal cancers

His result: All nine tests detect the vast majority of colorectal cancers and also many colorectal cancer precursors. If one follows the manufacturer's instructions as of which value a test is to be regarded as positive, then the frequencies of positive results differ greatly.

However, when the scientists adjusted the thresholds in the evaluation, all the tests gave very similar results.

"In this work, for the first time and globally, we present a one-off, direct comparison of the diagnostic value of a large number of quantitative tests in the same large group of investigators," Brenner said.

From these numbers, nationwide recommendations for thresholds of individual tests could be derived.

Lower threshold screening study

"This work gives Brenner and colleagues very specific recommendations on how to further improve the early detection of colorectal cancer," emphasized Michael Baumann, Chairman of the Executive Board of the DKFZ.

"It is important to offer people a low-threshold screening test in addition to the more elaborate colonoscopy, which remains the gold standard in colorectal cancer screening."

Five of the nine tests require a laboratory analysis. The remaining four tests can be performed and evaluated directly in the primary care and urological practice.

Even the test, which is evaluated using a smartphone app, provided reliable results - at least when performed by trained personnel.

The researchers published their findings in the journal "Gastroenteroolgy".

Third most common cancer worldwide

According to the DKFZ, colon cancer is the third most common cancer worldwide. About 1.4 million people get sick each year and 700,000 die. Even with colon cancer, the sooner you discover it, the better. Early detection can save lives.

Colonoscopy is the safest method of detecting colon cancer and its precursors. But when should you colonoscopy? The investigation is recommended if it has already come in the family to colon cancer cases.

In addition, all persons with statutory health insurance in Germany from the age of 55 have the right to a colonoscopy.

According to experts, however, it would make sense to aim at a new age limit and to recommend the investigation from the age of 50 years.

Unfortunately, the test procedure is complex and many patients shy away from it. Only 20 to 30 percent of the beneficiaries participate. (Ad)