Yes, it’s possible!
If I need to cut a piece of PVC that’s impossible to reach with a saw, I cut a small notch into the pipe with a utility knife and cut the pipe by pulling a nylon string back and forth in the notch. It’s not as fast or accurate as a saw—this 2-in. dia. pipe took about 5 minutes to cut through—but it’s a good trick in a tight spot. — Matt Boley