I have said a prayer for your wife and your family. I know how devastating that one word can be, but in the medicine of today, cancer is very beatable.
As for beating your self up over the why, there is just no answer to that my friend. This horrible thing we call cancer consumes almost all of our lives from one point to another. For a good long time after dad passed all I could do is wonder why... It doesnt help, all that you can do is put all your self into helping your wife get threw this and get better! And by the sounds of it the Doctors think it will be so..
Good luck and please keep us posted on how everything goes!
And good juju right to you both from Colorado. The maternal side of my family is well acquainted with this situation- and they all like to gather together and remind us men and boys just how easy we have it!