He also said he's sent about 400 of his patients to Basel because of the cost, and because the hospital there offers the best treatment.
Other treatment options include surgical removal of the primary tumor, and a drug called sandostatin that mimics the action of somatostatin and other drugs that are FDA-approved for kidney cancer that have also shown promise against pancreatic neuroendocrine tumors. Experts say there are also other radiotherapeutic agents currently in development.
Pancreatic neuroendocrine cancer often spreads to the liver, which experts believe happened to Jobs, but liver transplants are generally not an option for people with neuroendocrine cancers.
"People with liver tumors can live for very long. They are very slow-growing and they are not candidates for liver transplants," said O'Dorisio.
It's difficult to predict how long Jobs will survive, since survival depends on a number of factors, and Jobs has kept details about his condition private.
"Survival depends on the aggressiveness of the tumor and if it's malignant," said Ayala.
ABC News' Lara Salahi, Kristina Fiore, Becky Bielang and Scott Dunbar contributed to this report.