Cancer therapies that are precisely tailored to the patient can be highly effective. For patients with a tumor disease, from whom it is not possible to take the necessary tissue sample, a blood test is now available for the first time at the University Hospital Zurich (USZ), which presents them with an opportunity for personalized therapy.
Huge progress has been made in recent years where research and treatment options for many types of cancer are concerned. In particular, forms of personalized medicine that are tailored to patients’ individual constellation of symptoms are highly effective in many cases in treating cancer involving tumor formation. The starting point of personalized therapies is a molecular biological analysis of cancer cells (molecular tumor profiling), which provides treating physicians with information about which therapy can achieve the greatest effectiveness in an individual case.
Blood test provides new access to personalized therapy
For this molecular tumor profiling in the laboratory, a tissue sample of the tumor is required. Experts call such a sample a biopsy. The biopsy of a tumor in an organ such as the lungs, kidneys or liver is usually performed using a fine hollow needle under local anesthesia, but sampling is nevertheless a procedure with corresponding stress for the patient; in rare cases, it can also lead to complications. In a number of patients, a biopsy is not possible because their poor state of health does not permit such a procedure. Or a tumor is located in such a way that it cannot be accessed for sampling. Due to the impossible tissue sample, tumor profiling could not be performed in these patients so far; they therefore had no access to targeted, personalized therapy.
Patients have a new chance
In recent years, research has been carried out on innovative methods to detect the genomic changes of the tumor from the DNA present in the blood (liquid biopsy). Since the beginning of March, the Department of Pathology and Molecular Pathology at USZ has been the first institute in Switzerland to offer a liquid biopsy-based test. “This means that a group of patients can benefit from an ideally highly effective and life-saving therapy to which they had no access until now,” is how Dr. Martin Zoche, head of the Science department at the Department of Pathology and Molecular Pathology, sums up the introduction of the test. “It is precisely because we have often experienced successes with personalized therapies that this represents a real step forward in the care of patients in Switzerland.”
Blood test instead of another tissue sample
“The validity of the blood test is about as good as tumor profiling of the tissue sample,” emphasizes Martin Zoche. “The test therefore hugely complements our range of diagnostics.” However, the blood test will not replace the conventional molecular examination of tissue biopsy in the foreseeable future. A tissue sample is still necessary for the classification of the cancer and for further diagnosis. However, thanks to the blood test, it is certainly the case that fewer tissue samples will be required in the future. For example, the new test can also detect changes in the tumor genome that explain the tumor’s response to drugs or the development of resistance. “Also for these patients,” adds Prof. Holger Moch, Director of the Department of Pathology and Molecular Pathology, “the absence of another procedure to obtain a new sample is a tremendous relief.”