It's too soon in the diagnostic process to speculate on the outcome. He needs a lot testing before they can get a clear picture:

PET or PET/CT
MRI
CT
Chest xray
baseline hearing test
TSH baseline
Kidney (creatinine) clearance
and all kinds of other lab and bloodwork

Has all of this been done?

Was that .4cm that would be 4mm x 4mm x 2mm? 2mm is as small as can be detected by current scanning modalities. What did you mean by "all margins are involved"? They either get "clear margins" or not typically.

What staging? How invasive? What is the differentiation? These are questions to ask.

Many of us only had chemo and radiation and no surgery.

I would hazard a guess that if the lesion was that small there may be no node involvement. They can feel (palpate) a node above 1cm.

By floor of mouth do you mean under the tongue?

Sorry to ask so many questions I am just trying to get a clearer picture so we can appropriately respond to you.

Is he being seen at a Cancer Center or Comprehensive Cancer Center? If not, I would strongly urge you to get a second opinion from one, if nothing else. It is critical that this be done PRIOR to starting treatment.

I checked there are none in Rhode Island but here is a link to the list:

http://www3.cancer.gov/cancercenters/centerslist.html#L25