Everyone is different. This statement also applies to our health. Cancer, in particular, can look and progress differently depending on the individual person. That’s why every patient ideally also needs a customized treatment that is tailored to their individual needs. But how feasible is this idea?
Our genetic makeup is unique. As a result, cancer can be caused by different factors in different people. What's more, every patient responds differently to drugs and specific treatments. Personalized medicine promises to solve these problems – therapy that considers all characteristics of the patient and his disease. After all, cancer is a disease that is as individual as the people who are affected by it.
"From the outside, colon cancers for example seem to be similar or at least comparable. However, at the genetic level, they often have very different causes that also require different approaches to treat the patient," says Prof. Nisar Malek, Medical Director of the Clinic for Gastroenterology, Hepatology and Infectious Diseases at the University Hospital Tübingen and Chairman of the Center for Personalized Medicine (ZPM) Tübingen.
Personalized therapy not only looks at the type and stage of cancer, but also includes the patient's personal characteristics such as age, body weight, kidney and liver function, possible concomitant illnesses and social situation.
Biomarkers and choosing the right treatment
Experts agree: cancer should not be treated according to standard guidelines. A personalized therapy requires more than a treatment based on the type and stage of the disease. Age, body weight, kidney and liver function, perhaps existing concomitant diseases and the social setting of the patient are also playing a role. Yet it is primarily the tumor biomarkers – measurable biological characteristics – that play a key role.
Prognostic and predictive biomarkers are imperative to determine the right cancer treatment. Prognostic biomarkers indicate the likely and expected disease progression in the individual patient. In this case, the initial baseline value is measured and checked to see how quickly it increases. The choice of treatment strategy is based on this value. Predictive biomarkers make it possible to state how effective a certain treatment is and how a patient responds to it. To do this, the change in a specific gene is reviewed for example. The treatment may vary depending on the occurrence of a particular biomarker. A clear distinction between the two markers is not always possible.
Genetic mutation is an essential cancer cell characteristic. It amplifies certain signals or signaling pathways, which in turn promotes tumor growth and spread. That’s why a targeted cancer therapy focuses on blocking these signals and signaling pathways. This type of therapy is an option to treat breast, colon or lung cancer for example since many of these cancer cell mutations are already known, allowing us to specifically target them.
In an interdisciplinary exchange, doctors want to find the best possible treatment method for each patient. In this way, the patient receives an individual therapy made to measure.
Targeted cancer therapy
"Personalized medicine is most tangible and advanced in oncology because we have many new drugs available in this area that allow a targeted disease intervention," explains Prof. Malek.
In this treatment, monoclonal antibodies are used at the outside of the cell to inhibit growth and proliferation signals from getting to the tumor cell for example. Unlike tyrosine kinase inhibitors – "small molecules" – that penetrate the cell and interrupt the signal chain. So-called angiogenesis inhibitors impede the blood flow and thus the blood supply to the tumor tissue, enabling the immune system to attack it.
Unlike this targeted therapy, aggressive chemotherapy attacks all fast-growing cells to where healthy cells are also damaged. This treatment is very nonspecific and has severe adverse effects – drawbacks that are non-existent in personalized cancer therapy.
The choice of therapy is most notably based on genetic tumor profiling. "We also include immunotherapy, peptide vaccines, and individualized radiotherapy at this point. From my perspective, the new technologies and the interdisciplinary exchange have opened up further treatment options, especially for patients with advanced cancer where we used to be unable to offer any other treatments," Malek adds. The interdisciplinary exchange takes place as part of so-called tumor boards, where experts from different medical disciplines discuss and choose possible treatments for individual patients. A combination of different treatment approaches will be used in the future to ensure that patients receive the best possible treatment for their individual genetic profile.
New findings from research and the ever-increasing amount of data are constantly advancing the personalization of cancer therapy.
Personalization thanks to big data
Today, we have access to various types of drugs that have a targeted and successful impact. Having said that, the growth and spread of tumors cannot always be prevented or inhibited. That's because tumors often exhibit a variety of mutations where the right drug has either not been developed yet or the mutation itself is still unknown. What’s more, tumor cells multiply indirectly in some cases and these paths have also not been discovered yet. All of these difficulties need further extensive research.
Medical science is making progress daily when it comes to disease research and new treatment options. These advances result in ever-increasing amounts of data. As is the case in many other areas of life, big data also plays an increasing role in medicine. Research data and biobanks are fundamentally important for personalized medicine. Patterns can be detected if more data on the different types and characteristics of cancer and the treatment is available. This also increases the chances of a personalized therapy that is customized to the individual person.
The article was written by Elena Blume and translated from German by Elena O'Meara. MEDICA-tradefair.com