I'd rather that a genuine "AI" didn't drive my car thanks. On the other hand, a computer system with outstanding sensors, control and prediction systems... yes.
The problem with the cure for cancer is that most people don't understand that cancer is not a disease as such. It's "just" the body's own cells mutating/malfunctioning, which they do all the time, and getting themselves into a state where they are not shut down automatically (the fate for most mutated cells) and reproduce in an uncontrolled way. If cells never mutated then we would not exist, it's a fine balance. So targettting our own cells which are malfunctioning when our own body's defences against malfunctioning cells have missed them is a tall order.