Cancel buttons are step-dependent and application-dependent.
Suppose, for example you have a shopping cart. At the first step (say, log in) cancel should probably send you back to the cart screen (the last page). But say 3 steps in, should it still redirect to the previous screen? No, it should go to the cart screen again.
Thus, no helper tags Use something similar to Sevenwulf suggested and you should be good to go.