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Liquid biopsy: blood test shows treatment success of colorectal cancer


Blood test reveals risk of relapse after colon cancer treatment
Colon cancer is the second most common malignant tumor in men and women in Germany. More than 25,000 Germans die of it every year. Liquid biopsies in the form of a blood test are said to make cancer easier and sooner to recognize and therefore easier to treat.

Colon cancer is one of the most common cancers
Colon cancer is one of the three most common types of cancer in Germany. Almost a fifth of those affected have a family history. But people who suffer from inflammatory bowel diseases such as ulcerative colitis or Crohn's disease also have an increased risk. In addition, lack of exercise, smoking, alcohol consumption and malnutrition, such as a very high-fat and meat-rich diet, are among the factors that increase the risk of colon cancer. According to health experts, this cancer is often curable if diagnosed early: early detection can save lives. So-called liquid biopsies can be helpful here. A new study shows that this method gives relatively reliable results.

Relapses often occur in patients
Experts say colorectal cancer patients often relapse even after the tumor is removed. The question of whether the operation has helped or not often worries patients for a very long time. A blood test can show you whether you won the fight against cancer or not. This is the result of a study by researchers from the Institute of Medical Research in Victoria, Australia, and Johns Hopkins University in the USA. As part of a study, they used a relatively new technique called liquid biopsy to test the blood of 230 patients who had surgery for colon cancer. The study, the results of which were published in the journal "Science Translational Medicine", showed that liquid biopsies can be used to check whether cancer patients are likely to be permanently cured or to expect the disease to return.

Liquid biopsy for colorectal cancer diagnosis
The liquid biopsy for diagnosis of colorectal cancer had been tested at MedUni Vienna years ago. "Liquid biopsies take advantage of the fact that tumors and their metastases secrete tumor cells and fragments of tumor DNA, which then circulate in the blood," the scientists explained in a statement at the time. In their view, “establishing liquid biopsies as a standard procedure would be a milestone in the course of diagnostic tests and thus in the treatment of metastatic colorectal cancer.” Earlier studies have shown that “this technique is sensitive enough, tumor DNA fragments in cancer patients in the advanced stage, ”said Bert Vogelstein, co-director of the Ludwig Center at Johns Hopkins University, according to a report by the specialist magazine“ EurekAlert! ”“ But the new study brings us a big step closer to the actual goal because it suggests that it can be used to identify residual diseases in early-stage patients.

Test shows who needs further treatment
In their study, the researchers examined patients whose cancer was already quite advanced but had not yet metastasized. Although a large number of these patients can be cured, some of the tumors can be preserved so that the disease threatens to break out again. Blood samples were analyzed several times by the study participants during the therapy and were then observed for two years. Neither patients nor doctors were informed about the results of the tests. It was shown that 79 percent of the patients who still had tumor DNA in their blood relapsed. With negative tests, however, this rate was only 9.8 percent. It can be concluded from this that doctors could use the test to determine with relative certainty who urgently needs further treatment. A negative result, on the other hand, can reassure patients that they are 90% likely to be healed. (ad)

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Video: Liquid biopsy in daily clinical practice (January 2022).