One thing’s for sure about the Cancel action in a form: it is a negative within the context of Proceed as the positive.
Then again, in the context of what the user’s goal is, the positive and negative may be one or the other.
For example, in a 5-step interaction to fully complete the user’s profile, of course, as the designer, the positive action for you is the Proceed until the 5 steps are completed.
However, this depends on the user. Say user reached step 5 and a personal information is being asked and it’s not agreeable, then what could be a positive interaction for him/her?
A Cancel or a Skip & Save?
To keep it simple, design with the user’s best interest in mind.