if oral cancer spreads, they say it usually spreads to the aerodigestive tract, so lungs, esophagus, trachea, stomach, intestines, colon and lymph nodes too. So they usually pay close attention to those and do a eyes to thighs scan to check all of those areas.
As stated before, bumps and sores can just be due to that you had surgery recently and everything is overly sensitive, plus lack of feeling in some areas makes it difficult to know if you chew on ur tongue, or burn it sometimes too which can cause sores!!

Hope this doesn't come back for you again, but you have fought hard so far, so keep up the good fight.