Thursday, "Jeopardy" Host Alex Trebek, 78, shared the news with the world that he has been diagnosed with stage four pancreatic cancer.

He said in a video message: "Now normally the prognosis for this is not very encouraging, but I'm gonna fight this and I'm gonna keep working. And with the love and support of my family and friends, and with the help of your prayers also, I plan to beat the low survival rate statistics for this disease. Truth told, I have to! Because under the terms of my contract, I have to host 'Jeopardy!' for three more years!"

We think of people like actor Patrick Swayze, who lived about a year with the diagnosis and died at age 57. But we also think of Apple Founder Steve Jobs, who died at age 56 after living eight years with the cancer.

What is the prognosis for people diagnosed with pancreatic cancer today? Dr. Jeff Yorio of Texas Oncology says that even at an early stage, it's an aggressive type of cancer. "The long-term prognosis is really poor," he says. About 10 percent of people diagnosed with pancreatic cancer are alive five years later.

The problem, he says, is where the pancreas is located. It's behind the stomach, by the intestines, the gall bladder and the liver. "It's a high real estate area," he says, not unlike downtown, where multiple roads (think ducts and blood vessels) lead to there.

Often by the time people experience symptoms, it has either spread locally or it's involving blood vessels that are connected to other areas and cannot be surgically removed.

The symptoms include a sharp pain in the middle of the back, difficulty digesting or vomiting, unexplained loss of weight, or jaundice with yellowish eyes, skin or dark, dark urine. Sometimes people will be recently diagnosed with diabetes, which is actually the cancer affecting their pancreas.

There are two main types and which type you have makes a difference: Adenocarcinoma, which Swayze had and Trebek has, is the most common, with about 85 percent to 95 percent of all pancreatic cancers being this type. The other type is neuroendocrine, which Steve Jobs had. Neuroendocrine is a much slower growing cancer, which is probably why Jobs was able to live with it for years.

People get diagnosed by doing a Cat scan or MRI of the abdomen or an endoscopic ultrasound, followed by a biopsy of the mass.

Like many cancers, obesity, lack of exercise, diabetes, heart disease, and smoking seem to increase the risk factor, but, says Yorio, he's seen people just like Swayze, who were superb athletes, get diagnosed with it.  "There's also some randomness to it. ... there's some element of bad luck going on."

There's also some genetic connections, too. Now, he says, whenever someone is diagnosed with pancreatic cancer, he'll recommend doing genetic testing to rule out mutated genes, like the BRCA gene, that is also associated with breast cancer.

RELATED: Should you get genetic testing for cancer?

Whenever someone is diagnosed, Yorio discusses what the options are based on how much their disease has progressed. He'll talk about what would happen if they did not do any treatments and what the side effects might be from treatments like chemotherapy or radiation. "We want people to try to understand their disease as much as they can," he says. "They might make different decisions if they understand what's the future. We want to provide hope as best as we can. (We tell them) here are different options."

New research is being done, including clinical trials in which Texas Oncology patients are participating, but pancreatic cancer doesn't get as much research attention as things like breast cancer and lung cancer, he says, even though it is the third leading cause of cancer death in the United States.

"It's been a more difficult cancer to treat and attack," Yorio says.  "As we've made vast improvements in other cancers, we've made baby steps in pancreatic cancer and have miles to go."