It is by definition a preventative measure. Otherwise, it's no different then any other cancer treatment in that it has the same fundamental weakness working against it: natural selection.
If the cells knew when they were supposed to die, then it wouldn't be cancer.
If the cure is telling the cells when they're supposed to die, then the cells that don't listen survive, ergo the cancer survives.
Which, in the sense of (non-preventitive) treatment, makes it a problem of universal targeting.
If the cells knew when they were supposed to die, then it wouldn't be cancer.
If the cure is telling the cells when they're supposed to die, then the cells that don't listen survive, ergo the cancer survives.
Which, in the sense of (non-preventitive) treatment, makes it a problem of universal targeting.