Hello Michael,
My mother-in-law had 1/2 of her tongue removed and some of the lower base of the right side in March 2010. She was told that they removed everything plus a good amount to avoid reoccurance. Therefore no additional medical treatment was needed.

May 2012 she noticed a lesion on her cheeks and gums. She went to the dentist and was told to see her oncologiest. The cancer on her cheek muscles was the size of a marble. Her right lower jaw was partially "eaten" by the cancer. 10/10/2012 in Asia she had another radical surgery which was partial removal of her lower jaw and reconstruction. Her cheek muscles were scraped up to the point allowed as to not reach the skin. Because it was detected late it was considered T4A (Tumor that is locally advanced but surgically resectable and therefore salvageable). It still salvageable by radical surgery, radiation and chemo.

Looking back, I wish the did the radiation. May be she should not suffered the second surgery. In my opinion listen to the doctors and do the most aggressive step offered. Better to do it now than later when it has progressed.

My thought and prayers are with you. God bless.