What is cancer? An interview with Prof Dr Bart Neyns (VUB-UZ Brussel)

Bart Neyns is an authority in the field of immunotherapy

Saturday 4 February is World Cancer Day, the day when the world remembers the impact of cancer. But what exactly is cancer? How does it arise? And what different treatments exist? Prof Bart Neyns, clinical professor at the Faculty of Medicine of the Vrije Universiteit Brussel (VUB) and head of the Department of Medical Oncology at the UZ Brussel, provides answers. Bart Neyns is an authority in the field of immunotherapy, a revolutionary way of treating cancer. By combining knowledge and experts on cancer, UZ Brussel and VUB want to contribute to better social awareness of cancer and cancer research.

Prof Bart Neyns is head of the Medical Oncology Department at UZ Brussel. He obtained his medical degree at the VUB after which, as a trainee for the Fonds Wetenschappelijk Onderzoek (FWO), he conducted four years of pre-clinical research into the molecular genetic background of cancer cells. Since 2007, he has supervised several phd, master and bachelor students as a clinical professor at the Faculty of Medicine of the VUB. Together with his colleagues, he is committed to several innovative studies on cancer treatments, for which he has also been supported several times by well-known associations such as Kom op tegen Kanker and Stichting tegen Kanker. His scientific work was awarded the Hilde Bruer Prize in 2013 and can be accessed in more than 200 PubMD cited publications in high quality medical scientific journals.

Dear professor, can you briefly explain what exactly cancer is and how it arises?

Cancer is a disease process caused by an uncontrolled proliferation of cancer cells, which arise because the genetic material of a normal cell becomes damaged. This gives rise to an uninhibited and uncontrolled growth and proliferation of cells. When the cancer cells spread to other parts of the body, we speak of metastases, which in the worst cases can lead to the death of the patient.

When cancer is mentioned, the word ‘tumours’ is also often dropped. So what is the difference between a benign and malignant tumour?

A tumour is a swelling, a type of structure that forms extra in the body when it should not be there. This swelling can have different causes and be either benign or malignant. We speak of a benign swelling or tumour when a clear distinction can be made to where a tumour forms. Unlike a malignant swelling, a benign swelling will not grow through other tissues or metastasise to other organs. As a result, it is often possible to remove a benign tumour in its entirety with surgery.

A malignant tumour, on the other hand, is more difficult to remove because it spreads further in the body and settles into normal tissue. It can therefore metastasise and form new growths from a distance. In some cases, a benign tumour can become malignant at a later stage when the cancer cells become increasingly different from normal cells and start dividing uncontrollably. It is therefore important to closely monitor the abnormal cells and see whether or not surgery and additional radiotherapy or medical treatment is necessary.

Thanks to research in medical oncology, different treatments are possible depending on the diagnosis. Known cancer treatments are chemotherapy, radiotherapy and hormone therapy. But your clinical research focuses on a more innovative cancer treatment: immunotherapy. Can you explain what exactly that entails?

Immunotherapy is an umbrella term for different treatments, some of which can be very different but share a common goal. Namely, to encourage and mobilise the body’s own immune system to attack cancer cells. During immunotherapy treatment, the immune system is additionally supported or activated so that it can be mobilised, for example through the use of therapeutic antibodies, to more actively resist and destroy cancer cells.  So unlike chemotherapy or radiotherapy, immunotherapy does not target cancer cells directly, but rather works with the patient’s own immune system to attack cancer cells.

What types of immunotherapy are there?

Several types of immunotherapy are possible. The main types to boost one’s own immune system include so-called immune checkpoint inhibitors, therapeutic cancer vaccines, TIL therapy, CAR-T cell therapy and cytokines. The most successful way to treat cancer cells is with checkpoint inhibitors (‘Immune Checkpoint Inhibitors’) that boost the patient’s immune response. The checkpoint inhibitors bind to specific switches on the immune cells or cancer cells to shield the negative regulatory mechanism allowing them to work harder.

Another, successful form of immunotherapy is CAR-T cell therapy (‘Chimeric Antigen Receptor T-Cell’). In this, white blood cells or T-cells are isolated from the body and genetically manipulated in a laboratory so that they are equipped with a new receptor. This way, the body’s own immune cells can still recognise and detect cancer cells. Today, CAR-T cell therapy is only used in haematology.

Recently, immunotherapy is also possible in patients with melanoma, which is one of the most aggressive forms of skin cancer. However, your research has shown that immunotherapy produces remarkably positive results in melanoma patients with metastases. Can you elaborate on this?

We have actually been shaping immunotherapy for patients with melanoma since 2001. Although we have been working on it for more than 20 years, the big breakthrough came with the ‘Immune Checkpoint Blockade’ which was first used about 15 years ago. So almost 2 decades later, there are patients who have remained cured thanks to this treatment. You could say that today we can still completely cure almost 1 in 3 patients with metastatic melanoma with these checkpoint inhibitors.  

In addition, of course, our researchers also focus on patients who cannot yet be helped sufficiently with the available forms of immunotherapy. But here, too, we have recently made progress. Indeed, we have succeeded in making the disease disappear in some patients through more innovative treatments, such as injecting dendritic cells into the tumours themselves. This is obviously a hopeful sign to both patients and doctors who will embark on treatment pathways in the future.

Learn more about immunotherapy research at the VUB


More information on immunotherapy at UZ Brussel:


More information on the Paul De Knop Fund for Immunotherapy: