Steve Jobs, the inventor and co-founder and former CEO of Apple Inc., died Wednesday at the age of 56 after a fight with advanced pancreatic cancer.
Even though Jobs underwent a liver transplant in 2009, medical experts speculate that his cancer probably came back or spread, thereby causing his death, the Associated Press reported.
Pancreatic cancer expert Dr. Steven Libutti, director of the Montefiore-Einstein Center for Cancer Care, told Fox News:
"The liver transplant could have been for a metastatic tumor, and the most common place for a neuroendrocrine tumor of the pancreas to spread is the liver. What (could've ultimately happened), patients with metastatic neuroendrocrine tumors to the liver generally on average, can live seven, 10, 15 years after diagnosis. So, it fits the timeline."
Jobs was private about his health problems, and never disclosed whether, after the 2009 liver transplant, his cancer had spread further to his lymph nodes or liver, the Associated Press reported.
According to news reports, back in 2004 Jobs underwent successful surgery for a pancreatic neuroendocrine tumor. The tumor is a rare type that comprises just 5 percent of pancreatic tumors, according to the Memorial Sloan-Kettering Cancer Center. The tumor type is more slow-growing than other types.
The type of pancreatic cancer is usually only found when imaging procedures are done for other health issues. Treatments include surgery, hormone therapy, radiation or chemotherapy, MIBG radiolabeled therapy (a nuclear medicine technique) or other more early-stage approaches, according to Memorial Sloan-Kettering Cancer Center.
MyHealthNewsDaily reported that it's difficult to detect pancreatic cancer until it has already entered its late stages and spread, and that symptoms can be hard to pinpoint to the cancer.
"The early symptoms are very non-specific," Julie Fleshman, president and CEO of the Pancreatic Cancer Action Network, told MyHealthNewsDaily. "It's often not until a patient has become jaundiced that most physicians look deeper."
Not many people -- just 4.4 percent -- of people with pancreatic cancer survive longer than five years, USA Today reported. Jobs lived for seven years after it first became known that he was diagnosed with the cancer.
The Wall Street Journal reported that the number of new cases of pancreatic cancer is actually declining, likely because of decreasing rates of smoking. However, the cancer is still very deadly -- the fourth deadliest cancer for men, and the third deadliest for women, according to the National Cancer Institute.
Patrick Swayze also reportedly battled pancreatic cancer; the actor died from the disease in 2009, though he had a different form of the disease from Jobs, WebMD reported.
For Steve Jobs' medical timeline, click here.