Earlier this week, longtime “Jeopardy” host Alex Trebek revealed he was diagnosed with stage 4 pancreatic cancer, a disease that affects thousands of Americans every year.

In a video, Trebek announced the diagnosis and said he plans to fight it.

“Now, just like 50,000 other people in the United States each year, this week I was diagnosed with stage 4 pancreatic cancer,” he said while standing on the “Jeopardy” stage. “Now, normally the prognosis for this is not very encouraging, but I’m going to fight this, and I’m going to 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.”

The 78-year-old continued with to joke about how he will keep working because of his contract.

“Truth told, I have to, because under the terms of my contract I have to host ‘Jeopardy’ for three more years, so help me keep the faith and we’ll win, we’ll get it done,” Trebek said.

The unsettling announcement has many wondering why there is no strong form of effective treatment against stage 4 pancreatic cancer, which only has an estimated five-year survival rate of 3 percent.

This type of pancreatic cancer is known as one of the most aggressive cancers because of where it grows in the body. Pancreatic cancer is found so deep in the body and spreads so quickly, that it can often spread rapidly before symptoms are even noticed.

The symptoms for the disease include jaundice (yellow eyes),, dark urine, itchy skin, belly or back pain, weight loss, and poor appetite. Additionally, another early sign might be a blood clot in a vein called deep vein thrombosis or even diabetes.

Despite the symptoms, Dr. Dmitri Alden, an oncologist at Lenox Hill Hospital in New York City, said that very few people with pancreatic cancer are diagnosed in the early stages of the disease.

“The problem with this cancer is the fact that it’s silent and there’s no screening for it,” he told Healthline. “There’s nothing for pancreatic cancer short of doing a CAT scan every year, which is impossible to imagine because of the radiation and because of the economics of the country.”

If the tumor is found early and is small enough, it can be treated with surgery to fully remove the cancer. In some cases, doctors may use chemotherapy to shrink or the slow the growth of the cancer. Other treatments include radiation therapy.