Most cancer patients die as a result of metastasis, i.e. when the cancer spreads to other parts of the body. Metastasised tumours can generally not be treated successfully. Current treatments – such as chemotherapy, radiotherapy, or “targeted drugs” – mainly aim to alleviate the patients’ complaints and prolong their life. Cancer cells are able to multiply and spread because they are normally invisible to the body’s immune system. Working with the Swiss firm Philogen, the Maastricht team has developed a method to stimulate the immune system to attack and destroy cancer cells.
Immune response
The new treatment starts with irradiating the primary tumour. This causes major damage to it, releasing signalling substances that are recognised by the body’s immune system. Not only are tumour cells destroyed directly by the radiation, an immune response is also instigated. Dr Philippe Lambin, professor of radiotherapy, explains: “That immune response is not powerful enough to destroy cancer cells and any metastases. To get it to actually combat the cancer cells, we need to ‘trick’ the immune system.”
A bit of a nudgeMost tumours appear to have a single common feature: they all contain a specific point of recognition that is absent in healthy cells, namely the extra-domain B of the protein fibronectin. The new immunotherapy involves the use of a substance (an immunocytokine) that binds specifically to that part of the tumour. In this way the therapy is specifically targeting the tumour. Karen Zegers, who carried out the study together with Nicolle Rekers, explains: “The immune response that has already been instigated by the radiation is reinforced enormously after administration of the targeted immunotherapy. In our experimental models, no less than 75% of the tumours disappeared completely.”
Follow-up“Our study has shown for the first time that we can combat cancer cells effectively by using this combination therapy”, says Prof. Lambin. “Our latest results – which have yet to be published – also show that this treatment method has an effect on tumours located outside the irradiated area. This means that we should be able to not only increase the patient’s life expectancy but also actually cure tumours and their metastases.” In the next phase of the study, the Maastricht researchers will use the combination therapy for patients who have a type of cancer with limited metastasis.
An animation (in English) on
YouTube gives a concise explanation of the new therapy:
https://www.youtube.com/watch?v=xHbwQuCTkRc.