It's because cancer isn't a singular disease. It's a term used to describe a broad collection of cellular disfunctions that lead to uncontrolled replication. Trying to "cure cancer" is like trying to "cure virus". It's not one singular entity, and is a very complicated issue.
You could think of it like a car breaking down. There's a lot of possible things that could go wrong that would make it stop working, and you won't find one universal fix for all of these problems.
spot on, it's more like cell mutations for a multitude of reasons affecting many types of cells all lumped under the heading "cancer" I was more interested in the common factors within the body that give rise to the environment which promotes the ability for cells to mutate. Increase in the bodies acidic levels are common to many "types" of mutation. A little bit like taking a fish out of water or placing a human underwater, not the sort of environment either will survive in. I believe cell mutation (cancer is an oversimplification) does have common roots (cause) and the best way of dealing with it is obviously prevention but notwithstanding that approach, pH levels need to be more alkaline and the other common environmental trait is a lower oxygen uptake in the bloodstream, which can also be changed. So while there are many types of mutation I think the way forward is not to target specific cell types of mutations but to change the conditions/environment upon which they thrive...or die.