Dear Allthree,
You are in over my head here, but I will venture an opinion based on what I know. All the gastric cancers have similarities and differences, but the similarities may be more important when it comes to treatment. So far as I know, the therapies that work well for pancreatic cancer seem to be effective for cholangiocarcinoma and vice versa, except that it is important to realize that no conventional treatment is totally effective for either of them. It is a matter of buying time. So it may not be critical to know whether the point of origin is the pancreas, bile ducts, liver itself or the colon.
I will send what I have.
Good Luck,
Jeff