I read your other post that indicated that he was living in another country. If he was in the US, he could go to one of the major cancer hospitals and depending on the nature of the tumor (exact location and how invaded) perhaps get surgery and/or radiation. The tumor is located in an area where you need very special surgical skills. The pons as well as the rest of that part of the brain controls very sensitive functions - autonomic functions and a motor relay center.
Prognosis, sadly, without surgery is that he may only last 1 to 2 years but I found in a paper it can be longer - but with surgery he may last longer. I will send you a link to a paper.