Prognosis for Metastasized NET

My husband was dx with metastasized NETs originating in the small intestine 3 years ago. He's been on Sandostatin shot monthly since dx. Up until his most recent pet scan last week the shot seemed to be holding the tumors "at bay". This recent scan showed growth of the 3 large tumors in his liver to have grown and the tumors have also spread to his other lobe. His oncologist said "the next line of treatment would be a chemo pill called Afinitor but since you're not having any carcinoid symtoms that is your choice as to if you wanted to take it". Then he said, "there's nothing else we can do". I asked him about surgery on the liver "debulking" and he said "bc is in the other lobe and he's having no symtoms there's no reason for surgery" and he went on to say "the liver only needs 15% to function". After much research is clear that his once slow growing tumors have moved into a faster growing disease. I can see changes in him, that being more trios to the bathroom with diarrhea and he's more tired lately. But for the most part he still goes to work and dies his normal activities. Bc I don't feel like we're getting straight answers from his Oncologist i would like a straight answer. Understanding that whatever is said is not in stone, and generalized. I know there is no cure, I know their treatment was to try to keep the tumors from growing and spreading but we are at a crossroads now where the shot isn't working. He has heart disease, with 3 stents, middle age, overweight and works in a high stress environment. All things that don't help with his disease. From everthing I've read approx 17% make it to the 5 year mark. I need some insight as to what to expect since he doesn't want surgery or to take the chemo pill. Will he start to decline? Am I correct in what I've read in his prognosis? Is he at the advanced growth stage? I'm a person who NEEDS to know and the Oncologist saying , that's all we can do says a lot. Any advise would be helpful. Thanks.