Precision Medicine in Cancer Diagnostics and Therapy

Development of Precision Medicine in Cancer Diagnostics and Therapy

The years of progress in cancer therapy up to the beginning of this century were based on a generally applicable treatment strategy that could be applied identically to all patients. These were effective chemotherapies that were used in combination, possibly already accompanied by immunological therapy in the form of antibodies, which were used particularly for lymph node carcinomas – lymphomas – and for a certain form of breast cancer. This form of combined therapy – whether in combination with various chemotherapeutic agents or in conjunction with antibodies – has led to a significant improvement in prognosis and survival rates compared to earlier, less extensive forms of treatment: between 1960 and 2000, the 5-year survival rate for lung cancer increased from 12% to 18%, for lymphoma from 40% to 82% and for breast cancer from 63% to 82%.

However, the real breakthroughs in cancer treatment came with the help of functional radiological diagnostics using a combination of computer tomography and nuclear medicine in the form of PET-CT examinations and in molecular pathological diagnostics based on the findings of the Cancer Genome Atlas – a continuation of the Human Genome Project.

The Cancer Genome Atlas has created a “map” of molecular, genetically defined characteristics that regulate the growth of tumors in sometimes completely different ways. Based on the Cancer Genome Atlas and the molecular changes found, a completely new concept in the classification of cancer types has emerged: Based on these investigations, it was understood that, for example, lung carcinomas, breast cancer, colon cancer, but also black skin cancer – malignant melanoma – can be divided into subgroups according to their molecular characteristics: Today, for example, it can be claimed that lung cancer does not consist of a few histological subgroups as in the past, but of a large number of carcinomas with different molecular properties, each of which requires a therapy targeted to the respective molecular. Over time, this approach has been referred to as “precision medicine” because the therapy is directed precisely against the molecular alteration found in each case. Of course, such a therapeutic approach requires the necessary drugs to specifically inactivate the activated molecule that leads to the uncontrolled growth of a tumor.

As a result of this development, around 150 drugs have been approved by the European Medicines Agency since 2010 that specifically target such cancer-promoting molecular changes. This means that if molecular changes in the tumor cell exist and are detected, it is possible to prevent them from growing and spreading unhindered to organs other than the organ of origin – the classic characteristics of cancer – in the form of tablet therapy. However, changes in these molecular mutations often occur, so that the drug initially used is no longer effective. In such situations, either biopsies are taken from the tumor tissue again and subjected to a new molecular examination or a so-called “liquid biopsy” is performed, in which a blood sample is taken to detect circulating changes in the tumor’s genetic material – the circulating tumor DNA – which may be associated with a new molecular mutation in the tumor that can be treated again with targeted drugs.

A further advance in the last 15 years or so has been the clinical application of laboratory findings that tumors are able to inactivate the immune system directed against them. This leads to a corresponding exhaustion of the immune system, which in turn leads to the unhindered growth and spread of tumors. Antibodies have now been developed to counteract the tumor’s characteristic of active paralysis of the immune system, which are able to activate the body’s own immunological defenses against the respective tumor. This principle does not work for all types of cancer, but only for those in which certain characteristics are present – although these can still be recognized incompletely. However, this therapy concept works particularly well for lung carcinomas, renal cell carcinomas, tumors of the upper digestive tract or advanced bladder carcinomas, but also for black skin cancer – malignant melanoma. Given the fact that certain tumor characteristics can also predict the long-term survival of patients in this context, we also speak of “precision medicine” here. This is able to bring about long-term survival in patients who used to die quickly – as in the case of lung cancer.

“Theranostics” as an essential component of precision medicine

Finally, a key component of precision medicine is “theranostics”, in which nuclear medicine interventions, which were initially only used for diagnosis based on PET-CT, are also used to take therapeutic steps. This is increasingly successful and effective for advanced prostate carcinomas.
In the last two decades, cancer medicine has thus completely changed from a “one size fits all” strategy to an approach that precisely targets the characteristics of the tumor. Such “precise” steps have led to an annual decrease in cancer mortality of around 2% per year for the first time since 2016.

Precision medicine in cancer diagnostics and therapy at the Wiener Privatklinik

At the Wiener Privatklinik, we are proud to be able to offer our patients all of these methods – from comprehensive diagnosis to therapy – together with our partners as part of the Central European Cancer Center. Regularly held interdisciplinary tumor boards define the optimal – i.e. “precise” – therapy based on the tumor characteristics.