I knew someone who had oral cancer including a tongue tumor. I think cancer started on the tongue and spread to the rest of the mouth and the jaw. In his case, the cancer was too advanced and chemotherapy and radiation wasn't enough. So a part of the tongue and jaw had to be removed. He was in the hospital for months because he could not eat on his own and had to be fed.
I urge people to look out for signs of oral cancer and see a doctor as soon as it occurs. Early diagnosis is very, very important. Especially those with an increased risk, such as those with cancer in their family and people who smoke need to be extra careful.