No modern oncology without genetic testing

Medexpress: How is molecular diagnostics changing the approach to cancer and its treatment? What are the benefits of modern comprehensive genomic profiling?

A.T.: Genetic diagnosis is now a cornerstone of the diagnostic and therapeutic process in oncology. Until some time ago (about 20 years ago), molecular diagnostics were used in individual cancer treatments, such as for the inclusion of therapy in breast cancer with HER2. Then GISTs, colorectal cancer, lung cancer were added to this pool of cancers. And for the past five years or so, this pool has been growing. Now it's expanded diagnostics in breast cancer, prostate cancer, pancreatic cancer and ovarian cancer. Molecular diagnostics is most popular in lung cancer, since the most molecular therapies are available here. Also not to be forgotten are melanoma and the less common, diagnostically difficult cancers - sarcomas. The purpose of such diagnostics is, of course, to qualify for modern targeted therapies (so-called personalized medicine). But it should also be remembered that molecular diagnostics is used to make a proper diagnosis of cancer. It is on the basis of genetic testing, which is becoming more and more advanced, that the pathomorphologist obtains a genetic profile and can make a proper diagnosis (simple microscopic examination is no longer sufficient for this, especially in the case of complex tumors).

Proper diagnosis, qualification for therapy, but also monitoring the treatment process are important roles of molecular diagnostics, because the profile of a cancer cell changes during treatment. Initially, one drug works after identifying the correct genetic profile of the cell, but then, under treatment, there are changes in the genome of the cells by which they become resistant to treatment. But, a genetic test can be done again and another therapeutic target can be found, for another drug that will break this resistance. And the patient can continue to benefit therapeutically. One should also not forget a very important role of genetic testing - prevention. Here I am referring mainly to genetically determined cancers. Their number is about 10 percent. And here diagnostics plays a very important role, not only for the patient himself, but also for his family members, in whom prevention can be implemented early enough to detect cancer early. The role of genetics is therefore very important and already virtually inherent in medicine.

In addition, technologies are also modernizing, specializing. Until recently, simple, single-gene tests, targeting a single gene, a single change, were popular. Now, in diagnostics, we have more advanced tests that make it possible to evaluate a large number of genes associated with the process of ontogenesis, various mutations, as well as to assess so-called genomic signatures in a single test. Here I mean microsatellite instability, tumor mutational load or assessment of homologous recombination deficits. Technologies are also evolving in terms of the material from which we can perform genetic testing. When it comes to genetically determined cancers, such material was and is peripheral blood. When it comes to somatic lesions, of course, here we study tumor tissue, that is, tissue taken from the patient directly from the tumor. But also in some situations, for example, in lung cancer, in about 30 percent of cases there is no access to tumor tissue, because simply this material was used up in earlier stages of diagnosis, or it was non-diagnostic, that is, there was not enough tumor to examine. And here we have the possibility of performing a so-called liquid biopsy, that is, we take peripheral blood, but we do not evaluate the changes in nuclear cells from it, but we look for the so-called fraction of DNA derived from the tumor. From this pool of nucleic acids, we can already perform an extensive profiling, genetic study. And with this, a patient who has no tissue can have an examination of somatic (cancerous) changes for treatment or diagnosis.

Regarding the aspect of access and funding, it should be noted that funding for basic genetic testing is provided under the National Health Service. Advanced tests (small NGS gene panels) are also provided. And it is very good that this access is there. In contrast, in some cases we do not yet have access to more sophisticated genetic testing. In some cases, for example, lung cancer, ovarian cancer, sarcomas or cancers with an unknown starting point, comprehensive genetic profiling plays a very important role, because these cancers require a large gene panel. And this is what we are fighting for together with the PTO. We sent a benefit card to Minister Miłkowski indicating the need for such a test and funding for it. We have marked exactly the indications in which such tests should be performed, because we perform the most advanced ones in a selected population (it is not necessary to do them to everyone). Here we have great favor with the Minister. Therefore, we hope that this access will soon be for these cases of oncology patients. For people up to the age of 18 it is already there. It can be financed from the Medical Fund. But for adults it is not yet.