Where are we at today? Interview with Professor Dr Eva Winkler
“Precision medicine has arrived in cancer care”
Doctors are gaining an increasingly better understanding of why tumour cells develop and which molecular changes might cause cancer. One of their insights is that tumours – just like the patients themselves – are not identical. Professor Dr Eva Winkler, senior physician and head of the research group “Ethics and Patient-Oriented Care in Oncology” at the National Center for Tumor[J1] Diseases Heidelberg (NCT) and the University Hospital Heidelberg, explains how tailor-made drugs can make a contribution in this field – and what ethical questions we as a society ought to be discussing in this regard.
In precision medicine, doctors treat groups of patients on the basis of certain molecular characteristics that are specific to their illness. What can such treatments already do today – and what can’t they do?
Professor Eva Winkler: Precision medicine is enabling us cancer specialists to understand tumour diseases much better. For example, in the past, patients diagnosed with lung cancer were categorised according to two types of tumour: the small-cell and the non-small-cell variants. Today, we look at the changes in the genetic material and the metabolism of tumour cells and are able to identify many different subtypes, each of which is treatable with an appropriate drug. Around one third of all lung cancer patients carry such molecular markers on their tumour cells and are treated accordingly.
Are you saying that precision medicine has already been shown to have clear benefits?
Winkler: Yes, for certain types of cancer it’s already become a component of medical care. But it’s not suitable for every patient. It depends on the individual genetic profile of the tumour.
Can precision medicine cure lung cancer?
Winkler: So far, it’s been used mainly to treat terminally ill patients who can’t be helped through radiation or surgery. At this stage, the therapy is aimed primarily at alleviating tumour-related health problems and prolonging a patient’s life, while ensuring the best possible quality of life. With precision medicine, the range of possible side effects is smaller than with the chemotherapy that is normally used.
The tumour biology and the extent to which the disease has spread are decisive factors.
Why is it mainly patients with incurable diseases that are treated with precision medicine?
Winkler: In precision medicine, drugs are used for all patients whose tumour diseases show corresponding molecular docking points – unfortunately, until now this has only been the case for a small number of patients. Those suffering from certain types of leukaemia or from rare gastrointestinal tumours have good chances of recovery; for other patients, these targeted therapies are only used if the tumour is inoperable and the disease cannot be cured in any other way. The tumour biology and the extent to which the disease has spread are decisive factors.
Do expensive therapies like those offered by precision medicine have the potential for causing social inequality? Will a targeted treatment be available to everyone in the future?
Winkler: In Germany, the statutory health insurance funds operate on the principle of solidarity. All paying members support one another – regardless of their incomes or individual risks of illness. Therefore, everyone in Germany will benefit from this new type of medicine as soon as the relevant treatment is approved. This also applies to drugs that fall under the label of “precision medicine” – these are also known as “targeted therapies”. Within the framework of official guidelines, expert groups of scientists evaluate these treatments, pointing the doctors in the right direction by giving recommendations based on scientific knowledge and tried and tested procedures. These standard treatment guidelines are jointly developed by experts and medical societies.
What ethical questions does the analysis of the tumour genome raise?
Winkler: The tumour genome is considered less problematic to analyse than that of healthy cells, since it mainly contains changes that are not congenital but have been acquired over the course of someone’s life. However, this distinction is not always clear-cut. Genetic changes that have been detected from birth, and which we might pass on ourselves, are present in the tumour cells too. In some cases, they’re also responsible for the development of cancer. Therefore, doctors must inform patients that the genetic analysis might also provide them with information about the risk of disease in their descendants or relatives. So patients need to be asked in advance whether they want to receive this information in the first place. And they also need to consider how they are going to deal with it. After all, they may not be the only ones affected; others could be too.
Doctors – especially in the field of molecular genetics – need much more knowledge than they did in the past
Will these new treatment options change the doctor-patient relationship?
Winkler: Doctors – especially in the field of molecular genetics – need much more knowledge than they did in the past and they need to inform patients so expertly that the latter can themselves make well-informed decisions. Conversely, ordinary people also need to develop a basic understanding of biology, which is often not the case.
Is there a danger that people who don’t behave “in a health-conscious manner” will not receive therapy – despite having a high genetic risk of disease?
Winkler: From an ethical point of view, we’re not allowed to use such reasoning to deny people therapies. We’re not always free in our behaviour and there are many factors involved that are not necessarily controllable – whether we’re talking about healthy eating habits or quitting smoking. And socially deprived people would be doubly punished if they fell ill and received no treatment.
How is precision medicine likely to develop in the future?
Winkler: In the future, we’ll have a better understanding of the molecular mechanisms of disease development and a greater variety of suitable drugs at our disposal. As it stands, precision medicine has not been some kind of “silver bullet” that has cured diseases that doctors haven’t been able to cure before. One of the few positive exceptions is the treatment of chronic lymphatic leukaemia – a malignant blood-cell disease: with the help of a specific drug we’re able to “defuse” the modified enzyme that causes patients’ blood cells to divide unstoppably. We’ve also achieved good results with so-called CAR T-cell therapies.
What are they?
Winkler: These are forms of therapy in which the cells of the immune system are genetically modified so that they can identify the tumour as a threat to the body. They dock onto the cancer cells and destroy them. With this targeted treatment, leukaemia diseases can be cured to an extent not seen before in treatments with chemotherapy. Here [https://futurium.de/en/blog/fu...] you can learn more about CAR-T cell therapies.