What is the solution to the Problem of Child Cancer?

Why would an all-powerful God allow young children to have terminal diseases like cancer? Why would an omnipotent and omnibenevolent deity allow innocent younglings to experience such profound pain and early death? This question is different from any general questions concerning the Problem of Evil, because it focuses on a particular kind of evil that doesn't seem to lead to any greater good, doesn't seem to be necessary for free will and doesn't seem to be covered by any classical theodicies. There is a distinction between General Problem of Evil ("why would God allow evil in general") and Special Problem of Evil ("why would God allow this particular evil").