Question: what is cancer

Kristian Harder answered on 19 Nov 2013:

Cancer is what happens if body cells get damaged in a way that causes them to multiply in an uncontrolled way. Once they do that, there is a risk that they grow into other tissue and damage it, and if the affected tissue is part of some vital organ, cancer can be lethal. Even if organs are not affected directly, it can cause death due to serious chemical imbalances. (Actually I didn’t really know this and was often wondering why for example skin cancer can actually kill someone. Thanks to your question I finally took the time to do some reading about this! 🙂 )
One big problem with cancer, and one main reason why it is so difficult to cure, is that there are many many different kinds of cancers. It’s not so much a disease, as more like an entire *type* of disease. Many different kinds of cells can be affected, and there are many different causes. UV radiation in sunlight for example can damage skin cells to the point where they go nuts. Radioactivity can damage molecules and lead to similar effects. Chemicals, such as what you inhale when smoking, can also have such effects. But a lot is still unknown about cancer, and there is lots of research work to be done for future scientists. Will you be one of them? 🙂

Oh, and even though we as particle physicists are absolutely no experts on cancer, we do provide one excellent treatment option. Focused particle beams from our accelerators can be used to destroy tumours. If you have a single tumour, then this can be a lot better than chemotherapy because you can determine very precisely where you want to destroy tissue, whereas chemotherapy usually messes with the entire body somewhat.