...they are very similar in interaction, BUT are very different cases.Exit an app or process, vs. cancel an action (e.g. abandon a text field that might have taken a long time to enter stuff on). Exit can usually live with interstitials, but cancel often must be more inline. Or maybe even other methods of protection such as saving data, allowing exit, but then telling user they can go back to enter it again... Refer to clear fields in text entry as well...
Problem
Solution
Variations
Interaction Details
Presentation Details
Antipatterns