Cancer isn’t a single disease, so we can dispense with the idea of a single “cure”. There are over 200 different types, each with their own individual quirks.
Even for a single type – say, breast cancer – there can be many different sub-types that demand different treatments. Even within a single subtype, one patient’s tumour can be very different from another’s. They could both have very different sets of mutated genes, which can affect their prognosis and which drugs they should take. Even in a single patient, a tumour can take on many guises. Cancer, after all, evolves. A tumour’s cells are not bound by the controls that keep the rest of our body in check. They grow and divide without restraint, picking up new genetic changes along the way. Just as animals and plants evolve new strategies to foil predators or produce more offspring, a tumour’s cells can evolve new ways of resisting drugs or growing even faster.
Now, we know that even a single tumour can be a hotbed of diversity."Full article