Immunological tolerance to tumour cells

The immune system is the main protector of our health. Its main function is to differentiate between ‘self’ and ‘alien’, between ‘harmless’ and ‘dangerous’. This ensures the integrity of the body’s tissues, called tissue homoeostasis. Thus the immune system can eliminate unknown substances, disease-causing agents and damaged cells.

Cell mutations are constantly occurring in our body. Usually the immune system recognizes and eliminates abnormal and dangerous cells. Before a cell becomes malignant it takes many mutations. In this case, the immune system attacks the malignant cell. But how comes that despite all these safety measures cancer is so common?

Obviously, the control mechanisms of the immune system can fail. When malignant cells have survived in the body for some time, the tumour influences the immune system by developing so-called escape mechanisms. In various ways the tumour represses the body’s defence mechanisms and becomes invisible for them. The organism starts to accept the tumour as the body’s own cells although they harm the organism. This immunologic phenomenon is called tolerance. Only specific immunologic treatment can resolve tolerance.

Active versus passive treatment methods

Conventional cancer treatment today focuses on the deletion of cancer cells by surgery, irradiation or chemotherapy. Unfortunately, these methods cannot differentiate between diseased and healthy cells. Therefore, conventional treatment will always destroy healthy tissue, leading to side effects. The main problem is that in conventional medicine the patient remains passive, something is being done to her or him.

Immunological cancer therapy has led to a paradigm shift. Cancer is now viewed as a disease of the whole body, not just a local phenomenon. Specific immunological cancer therapy is intended to activate the body’s immune system enabling it to actively battle the disease. Apparently, it is not necessary to destroy each and every tumour cell. It has been proven that for overall survival as well as for an improved quality of life, a balance between the tumour and the immune system is more important. This is referred to as ‘recurrence free interval’, ‘stable disease tumour’ and ‘tumour dormancy’.