As some have said, categorizing his books can be subjective. I would say there is romance but the rest is difficult to describe. Horror? Well, we are talking about Stephen King but it's not a classic horror novel, in my opinion. The can opener scene is not easy to forget...read it. I loved it, but some fans didn't like it precisely because it isn't horror.
I'll read it, I actually own two copies, one of which I got for my birthday this year; That one is going on the bookshelf because it's in mint condition and still has the cover.