Cancer is not just one disease, there are actually about 100 different types of cancer, a tumour on the skin may be very different to a tumour in the gut. Cancer refers more broadly to abnormal cell growth. When something goes wrong in the cell cycle, the genes become unstable and the cancer cell may start growing out of control.
Once a cluster of cancer cells, growing uncontrollably (malignant tumours) get a blood supply they can effectively live forever! They can then spread to other parts of the body too, at which point it can be difficult to treat.
Overall it’s difficult to treat because cancer cells are your own cells, cancer research is looking for ways to identify particular tumours and target them with therapies that won’t be harmful to the patient, just the tumour.
Lots of people do research lots of different cancers, some of the major ones such as breast cancer are readily treatable if discovered early or lung cancer which is easily avoided most of the time by not smoking. Communication of this is important as well as research. However, more people could always be used to speed things along! It would just require more money, perhaps your school can have a Cancer Research UK event to raise some funds!
So I try and think of cancer as a set of Dominos shaped in a pyramid, one can hit two, they can hit three and so on. Imagine every single cell in your body has one of these pyramids and actually each layer is a gene. For cancer to happen you need a series of mutations to all occur in one cell, normally a stem cell as they are around the longest and have the most chance of getting enough mutations. So lets say every person gets one mutation every day, but remember the whole genome is only around 1-2% genes, and most cancer mutations have to be in genes, so most mutations will fall outside of the genes and have no effect.
Then it has to be a mutation that will actually cause damage, most won’t, if you have looked at DNA codon usage there is a lot of redundancy and there is a high likely hood that the mutation will have no effect. OK, so the mutation was in a gene, an important one, and it was able cause damage, then it is highly likely to be repaired, we are very good at repairing DNA damage but some mistakes slip through. So on day one, there was a damaging mutation to an important gene that wasn’t fixed, we can think of that as the first domino falling. Now the next day there is another mutation, but again it might not be anywhere important, it might not do anything and it might get repaired, and even if that happens it might be in one of the other 10 trillion cells in the human body.
For cancer to happen, you need multiple mutations in the same cell type in a variety of really important genes, normally you need to stop DNA repair, that helps you get more mutations, you need to learn to ignore signals from the body that tell you to die, so receptors and signals have to be mutated, you have to stop planning to die like cells normally do so you have to mutate your genes that control how often you divide.
There are also lots more different types of mutations that can cause cancer in combination, but they all need to build up in the same cell, knocking over more layers of bigger and bigger dominos until its too late. That is why you see most cancer in older people, because they have had time to ‘collect’ the mutations in the cells. But it’s also why there are so many different kinds of cancer, it depends on which cell type it started in, brain, heart, liver, lung etc, but also on which combination of mutations that turned it into cancer, that effects how dangerous it is, how fast it grows, does it spread. So even if two people have lung cancer it can be a very different type of cancer.
There are millions of people working world wide to cure cancer, every university has multiple labs all working on different cancer types, there are charities with there own labs, the problem is every different type of cancer requires a different cure and we don’t even know how many different types there are yet.