Breakthroughs in follow-up cancer diagnostics: Recurring cancer can be detected before it reaches full speed

A liquid biopsy using markers released into the bloodstream by cancer cells can reveal the possible recurrence of cancer and residual disease long before traditional methods — in Finland, the test is already in use at Docrates Cancer Center.  

Cancer treatment is becoming more and more personalised. In recent years, the greatest strides in personalised treatment have been made particularly through the development of the genetic and molecular profiling of tumors. The utilisation of information based on genetic diagnostics already offers cancer patients the opportunity to receive targeted treatment and avoid unnecessary treatment and the adverse effects it causes.  

Various tests utilising the genetic data of cells are also being developed for detecting cancer at an earlier stage. The latest addition is fluid biopsy, which can be used to detect signs of recurrent cancer in the bloodstream, sometimes up to months before conventional imaging or blood tests used in cancer treatment can detect these signs.  

Test results provide new information for optimising treatment decisions and follow-up

At the moment, the test can be used, for example, for intestinal, breast, lung and bladder cancers, both to determine the response to treatment and before starting pharmacotherapy after surgery or to predict a possible recurrence.

The test method is based on the identification of tumor DNA circulating in the bloodstream. A liquid biopsy can be used to identify microscopic tumors after surgery, a cancer developing at the molecular level or a recurrent cancer more quickly than the conventional methods by tracking tumor DNA released by the cancer cell into the bloodstream.

The test package is prepared individually for each patient

During the development phase of the test, the DNA of the patient's tumor tissue and healthy white blood cells are sequenced and compared with each other, and each tumor is given its own DNA fingerprint. After this, the circulating tumor DNA can be detected in the patient's bloodstream with great sensitivity and accuracy, even at a very low count.

The patient's cancer may not have necessarily recurred if tumor DNA is found in the bloodstream, but a positive test indicates that the chance of recurrence is considerable. A negative test result indicates that no tumor DNA has been detected and the risk of recurrence is low. The result of the test always requires a clinical interpretation. Doctors can optimise treatment decisions and follow-up according to the test results.

 Better treatment with fewer side effects

In addition to surgery, adjuvant therapies are often used in the treatment of cancers suitable for this test. These treatments can be rough on patients and significantly impair the quality of life. The new blood test will provide oncologists with important additional information to support treatment decisions and enable patients to receive better treatment.

Docrates Cancer Center introduced the new testing method at the beginning of 2023.

“In the best case scenario, we can detect cancers that are about to recur earlier than with conventional imaging methods and it may be possible to start treatment in time before the cancer, so to speak, reaches full speed,” says Docrates Cancer Center's Chief Clinical Director Juha Kononen.

“We will also be able to avoid or at least reduce the number of drug therapies that causes side effects if the test shows that tumor DNA from the cancer cells is not detected in the blood. Instead, we will closely monitor the situation according to an individually prepared treatment plan. We have already had cases like this. Naturally, patients are satisfied when they are spared from miserable adverse effects,” says Kononen.

The sensitivity of the method also has its challenges

The sensitivity of a fluid biopsy also has its challenges; it can detect a possible future recurrence of the cancer long before the cancerous tumor or tumors can be seen with conventional methods. And if the cancer cannot be located with imaging studies, it may not be possible to treat it.

“You could say that a positive test result in such a situation gives us information that the seed of cancer is in the bloodstream, but we do not yet know when it will start growing, if at all. However, this information helps doctors and patients to draw up a more effective and individual monitoring plan so that we are ready to begin treatment as soon as we know where the tumor is located,” says Kononen.

The advantages of the test also include freedom from radiation, unlike, for example, with CT or mammography. The post-treatment monitoring phase can, for example, alternate between blood tests and imaging tests and thus also reduce the patient’s exposure to radiotherapy.

“We cannot rely on just one test. We will continue to need imaging studies and other traditional methods. Like other diagnostic methods, a tumor DNA test alone is not yet sufficient, but it complements diagnostics in a special way,” says Juha Kononen.

Link to Docrates Cancer Center press release >