Pancreatic cancer has a dismal survival rate, surely one reason the business world has been abuzz in recent weeks over the gaunt appearance of Apple Inc. Chief Executive Steve Jobs. Jobs was diagnosed with pancreatic cancer in 2004 but underwent surgery. He said the tumor was caught early and that he had fully recovered.
Jobs had good reason to be optimistic at that time. The rare type of pancreatic cancer he was treated for is less aggressive and has a much better survival rate than most forms of the disease.
However, his disclosure about having a hormone imbalance indicates he may be dealing with a recurrence of the disease, some doctors suggest.
The pancreas, which lies deep in the abdomen behind the stomach, has two types of glands, exocrine and endocrine. About 95% of pancreatic cancers are exocrine tumors, usually adenocarcinomas, according to the American Cancer Society.
Exocrine tumors are often fatal because they're difficult to detect early, when the tumor is small. By the time cancer is diagnosed, it has often spread to other organs.
Jobs, however, was treated in 2004 for cancer of the endocrine glands in the pancreas, known as islet cell cancer or pancreatic neuroendocrine cancer. Islet cells release hormones important to digestion, such as insulin and glucagon.
People with the more common exocrine tumors have a five-year survival rate of only 5%. However, the average survival rate for people with pancreatic neuroendocrine cancer is more than three years. Some people survive much longer based on the tumor's subtype, size, whether it has spread and the patient's age.
In general, pancreatic neuroendocrine cancer is often detected early, typically grows slowly and can be treatable even after it has spread, said Dr. Heinz Lenz, a professor of medicine who specializes in pancreatic cancer at USC's Keck School of Medicine.
"These patients do significantly better," he said. "The treatments are different and are much better than traditional pancreatic cancer. I don't know if [Jobs] has active disease. But some patients can have some disease for years with no problems. These diseases can produce episodes with symptoms and then become stable again."
Pancreatic neuroendocrine tumors often secrete one of a handful of hormones, such as insulin or glucagon, that produce obvious side effects.
"These tumors produce hormones that can cause diarrhea, and people often lose weight," Lenz said. Jobs' description of his illness suggests "the tumor may be acting up a bit," he added.
Hormonal imbalances are common in people who have an active neuroendocrine tumor but would not be expected in someone who has been cured of the cancer, said Dr. Selwyn M. Vickers, chairman of the department of surgery at the University of Minnesota.
"If the tumor has come back after it has been removed, that is a sign the tumor is aggressive and growing," Vickers said.
People with a recurrence of pancreatic neuroendocrine cancer have a survival rate of one to two years, Vickers said.
"It's difficult to know what kind of hormonal imbalance he is talking about," said Dr. Gagandeep Singh, director of the liver and pancreas center at John Wayne Cancer Institute at Saint John's Health Center in Santa Monica.
"Some of these hormones can be managed," he said. "All you need to do is negate the effects of this excess hormone production, and there are specific medications that are available for that."
Although neuroendocrine tumors tend to be very small, it's also possible that so much of the pancreas was removed in 2004 that Jobs simply lacks the digestive enzymes to maintain his weight, as his statement implies.
"If there is a paucity of those enzymes, there is going to be a lack of absorption of proteins," Singh said.