I think you need to get another opinion as soon as possible, hopefully from a full staff, multidisciplinary cancer center. Time is of the essence, do not delay this step. Unless your father has significant distant mets or ones to the brain, this doctor is way out of line telling you something like this, (and even those people with advanced, additional organ disease do survive the process). Though I do not know the details of your father

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.