I really think this just speaks to the fundamental differences and the highly unique nature of each individual cancer. Although my SCC was in my mandible, my medical team's approach was to operate, then radiate.
I asked about that (not wanting to undergo the surgery) and the lack of chemo. They indicated that in my case, they wanted to remove the tumor mass first, since I was already at stage IV. Their concern was the potential for metastic spread.
As a result, I had the surgery (along with the left radical ND) followed by radiation 10 weeks later. No chemo because the primary was removed cleanly, and all margins and nodes were clear.
I think there are just too many factors to take into consideration for treatment to be the same across the board.
Wayne