Analyzing the key questions about Jobs' health

— -- USA TODAY asked experts to explain what might be causing new health problems for Steve Jobs, who was diagnosed with a rare form of pancreatic cancer in 2004.

Q: Is this grave news for Jobs?

A: Not necessarily, says Richard Goldberg, associate director of the University of North Carolina-Chapel Hill's Lineberger Cancer Center. Although Goldberg specializes in this type of cancer, called a neuroendocrine tumor, he has no personal knowledge of Jobs' health.

Jobs' weight loss could be a complication from his cancer surgery, or it could suggest that his tumor has returned.

Even if his cancer has returned, Jobs, 53, could live a long time, Goldberg says. Jobs' pancreatic tumor is quite different from the more deadly form that can kill within months of diagnosis. Jobs has a neuroendocrine tumor — located in the pancreas' hormone-producing cells — which grows very slowly. Some patients live as long as 20 years after diagnosis.

Q: Why would surgery make him lose so much weight?

A: Jobs had a complex operation called a Whipple procedure, which involves removing not only the tumor, but also the beginning of the small intestine, Goldberg says.

Losing so much of his pancreas, which makes the critical hormone insulin, could leave a patient diabetic, Goldberg says. The pancreas also makes enzymes to help digest fat. Without those, fatty food can pass right through the body without providing any nutrition.

Patients usually can take digestive enzymes with meals, Goldberg says.

Q: So why isn't his problem under control?

A: If Jobs' cancer has returned, Goldberg says, the tumor could be making an extra supply of hormones normally made by the pancreas. That also could make him lose weight.

Q: What's the treatment?

A: Doctors have four main options. They could give digestive enzymes, chemotherapy and drugs that turn off the hormone-secreting cells.

If the tumor has spread to the liver, doctors also could block the blood vessels that feed the liver to shrink the tumor.