Yes, you can! You will probably need more layers of pasta and sauce if you choose not to add meat. I used a lot of ground beef in with my sauce and this created the pan to fill up faster than I expected.  If you use a meat sauce, be sure to break the meat down into very small pieces so that it spreads out well and does not create an overly thick layer of meat.  The more meat you use, the less room you will have for layers of cheese and noodles.