It is very easy for the Commissioner to delete their contest(s), which removes them from the search results entirely and avoids confusion for players looking for your contest. I would highly recommend you clean up your contests by removing any duplicates you accidentally create, or any test contests you looked into and abandoned.
You simply need to log into the Settings page of your contest, and scroll down to the RED box called the "Danger Area". Within that box, you'll find instructions on how to Delete This Contest.
Here's a helpful video we made to illustrate this process.