Do I have to withdraw incomplete college applications if I've just changed my mind?

I’m currently deep into the college application process sheds tears and I’ve got most of my top choices’ applications done or almost done. However, there were a couple of schools where I started the application, but decided to change my mind and not apply there. Should I call/email the admissions office of those schools and tell them to withdraw my application or should I let it sit incomplete and (possibly) expire?