What is cancer?

Although much detail has yet to be added, biomedical research today knows, at least on a conceptual level, how cancer develops and progresses into a deadly disease. This, however, does not mean that all questions about the origin of neoplastic diseases are already clear. There are enough gaps in our knowledge to keep the research community busy for many years to come.

Question: What is cancer?

Answer: Cancer is a disease of the genes.

Mutations in genes that participate in directing cell division lead to the loss of control over cell proliferation. The immune system has the capacity to identify protein alterations caused by mutations in the gene that codes for this protein. Mutated cells, including cancer cells, are detected and destroyed at an early stage of their development by the defense mechanisms of our body. In this way, the immune system probably protects us from cancer for a long time, maybe even decades.

But just as with other organs, the capacity of the immune system deteriorates with age; the defense front begins to crumble. The increasing weakness of the immune system allows individual cancer cells to hide from scrutiny. In addition to passively hiding from the immune system, cancer cells develop mechanisms for active protection from immune attacks. Only once this is accomplished, cancer can develop into full-blown disease. The immuno-oncology point of view therefore suggests another answer to the

Question: What is cancer?

Complementary answer: Cancer is the symptom of an immuno-deficiency.

The development of cancer understood as a failure of the immune system to prevent uncontrolled proliferation of mutated cells has only very recently arrived in mainstream oncology. Changing perspectives opens the door to aspects of cancer that otherwise remain hidden. Considering only the cancer cell itself and its genetic alterations as targets for therapeutic efforts has prolonged the life of cancer patients. However, we are still far from finding a cure or at least a way of permanently controlling malignant growth. Immuno-oncology tries to see beyond the cancer cell and understand cancer as a complex tissue. Cancer is not just a pile of cancer cells, but a tissue with a defined fine structure that is critically influenced by, among other things, the immune system.