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Cancer prevention Can cancer be detected early via a blood test?
As with many other diseases, cancer also applies: the earlier the diagnosis, the better the chances of recovery. Hopes are placed here among other things in a blood test, which should make other investigations superfluous. But how far is research in this area? Experts give information.
One of the most common causes of death in Germany
Cancer is still one of the diseases most Germans die of. Health experts repeatedly point to ways to reduce the risk of personal cancer. In addition to a healthy lifestyle with regular exercise, balanced nutrition and the renunciation of alcohol and cigarettes, medical check-ups should also be mentioned here. In the future, a simple blood test could possibly lead to the diagnosis of cancer - or the all-clear.
About a year ago, a blood test for the early detection of cancer in healthy people had been announced. But can such a diagnosis really be made by a blood test? (Image: StudioLaMagica / fotolia.com) Can a blood test make mammography and colonoscopy superfluous??
Can a simple blood sample replace the invasive removal of tumor tissue? Can a few milliliters of blood even make mammography and colonoscopy superfluous? What's on the blood cancer test, the Liquid Biopsy?
These are the questions asked by the German Cancer Research Center (DKFZ) in a recent announcement on the occasion of World Cancer Day on 4 February. The experts inform about the current state of research: What is already possible today and what can be expected in the near future?
Early diagnosis
In recent years, research on a blood test for better cancer diagnosis has been reported repeatedly. Also scientists of the DKFZ were involved in the search for a test for early cancer diagnosis.
About a year ago, the Californian company "Grail" announced a blood test for the early detection of all conceivable cancers in healthy people, it says in the current release. The market launch is expected in 2019.
The experts of the DKFZ explain the biological background of the test: According to this, genetic material from cancer cells or whole cancer cells are continuously absorbed into the blood. Their detection is called "liquid biopsy" - liquid biopsy. Each tumor has its characteristic pattern of cancer-specific genetic alterations. Scientists can detect the cancer-typical DNA snippets.
Can survival be prolonged or quality of life improved?
"In many cases it is already possible to follow in cancer patients after the treatment on the basis of the detection of DNA in the blood, whether the tumor recurs. Therefore, the vision has developed that in the future tests on tumor DNA in the blood could also be used for the early detection of cancer. However, there are no data available yet. This means that the hypothesis underlying this vision must first be proven, "explained Peter Lichter, Head of the Department of Molecular Genetics at the DKFZ.
"Even if such proof could turn out to be technically feasible: As with other screening tests, it would have to be shown that it actually benefits people, meaning that it extends survival time or improves the quality of life," added Susanne Weg-Remers, who works at the DKFZ directs the Cancer Information Service.
Observation of the course of therapy
Holger Sültmann, head of the cancer genomics research group at the DKFZ, considers it only a matter of time before tests for tumor DNA in the blood in cancer medicine receive clinical approval. Initially, however, it will not be about cancer screening tests.
The development of tests to monitor the course of treatment of already diagnosed cancers is much more advanced. "Unlike tumor tissue samples, blood can be easily removed several times at short intervals. So we can track if and how long the cancer responds to a drug. This is important because cancer cells quickly develop resistance to many drugs, "says Sültmann.
In his opinion, it is still not possible to estimate when a DNA test for the early detection of cancer will actually be available.
Identify the most effective drug
According to the experts, the long-term goal is to use a blood test to identify the most effective drug for the individual patient - even without first having to analyze the tumor tissue.
Because many of the cancer-typical genetic changes that can be detected with the Liquid Biopsy, are the key drivers of tumor growth. Targeted drugs could block them and stop the cancer.
According to Sültmann, however, it is not yet possible to predict whether this will work at all and, if so, for which types of cancer.
He said, "I'm assuming that Liquid Biopsy will take a place in cancer medicine - for specific questions about certain cancers. But there will not be a general "cancer test" for the foreseeable future. "
New investigations still no routine applications
"Some patients who call us fear that the cancer will return and hope to see it as early as possible with a regular blood test. Others have the idea that using a Liquid Biopsy can avoid an invasive procedure to remove tumor tissue and wonder if that might be an option for them, "says Weg-Remers.
"Unfortunately, almost all of these new studies are not yet in routine clinical care and should only be used in patients if possible. For questions about the current state of developments in this field, the Krebsinformationsdienst is always happy to provide information - by phone or e-mail. "(Ad)