Azazel,
Both my parents died of cancer; my father had multiple myeloma (bone marrow cancer), my mom had pancreatic cancer. At the end, her various systems began shutting down, she was retaining fluids, and she swelled up like a jaundiced beach ball. She briefly recognized me, but was otherwise not lucid. She was on morphine for pain and just stared at the TV watching videos my dad brought to the hospital for her. My dad died a year later. He wasted away from about 200+ pounds to around 130 or so. Although he didn't come right out and say it, he was scared sh**less. He was disoriented; for example, the doctor would ask him if he knew his address, he would say yes and give the doctor his address from 10 years before. He was having paranoid delusions. In his work and in other areas of his life, he was used to bossing/bullying people around, and he had a very hard time coming to grips with the loss of control over his life. Control over his bowel movements became kind of a metaphor for his life. He would hold them in until me or my brother arrived at the hospital to visit. This gave him some amount of dignity even though it was hugely uncomfortable I'm sure. The night he died I helped carry him to the bathroom. He was just kind of a wasted skeleton at that point and his stools just let loose, no control whatsoever. He just looked at me with pure dread and said "uh oh" and he died a few hours later.
So, in other words, dying of cancer totally blows! Fortunately, my parents had done a lot of traveling and had seen me and my brother grow up, graduate from college, etc., and did not seem to have any regrets about missed opportunities and the like. I think that gave them some amount of comfort.
My wife is a children's cancer doc who used to work at City of Hope, and their bone marrow transplant unit is renowned. Steve Forman who runds the unit is very well-regarded and wrote the definitive text on bone marrow tranpslantation. Do yourself a favor and get a consult there. I think they will give you straight information about treatment options and rates of survival.