Sure you can but the plant is just doing what it is supposed to do normally so pruning it sure isn't recommended. The issue is the size/style of the cage, not the plant. Most just let it grow and drape back down over the cage.

You'll lose the future production so if you don't want more tomatoes from it, it's your choice.

Lots of discussions here about pruning that the search will pull up for you if interested.

Dave