If I'm not mistaken, wasn't that study with the Omeprazole and the stomach cancer done on rodents? I think some people will do a period of time on it and a period of time off of it, to reduce the risk, just in case. Scarlett, who is severely affected, has been on Gabapentin, Previcox, and Omeprazole (with an occasional Tramadol, if needed), for about 2.5 years and her bloodwork always comes back perfect-- knock on wood. I also agree with the person who said that they would rather their dog have a good quality of life for the time she is here, using meds that do truly help her.
How about contacting Dr. Rusbridge for a consultation? You can send her the MRI results and explain what is happening and she can get you on the right meds regime. I don't think a consult is too expensive and it would give you peace of mind.
In my experience, I think the CSF inhibitor is very important for these dogs.
Holly, Oliver, Rosalita, and Scarlett