Causes

It's not clear what causes pancreatic cancer. Doctors have identified some factors that may increase the risk of this type of cancer, including smoking and having certain inherited gene mutations.

Understanding your pancreas

Your pancreas is about 6 inches (15 centimeters) long and looks something like a pear lying on its side. It releases (secretes) hormones, including insulin, to help your body process sugar in the foods you eat. And it produces digestive juices to help your body digest food and absorb nutrients.

How pancreatic cancer forms

Pancreatic cancer occurs when cells in your pancreas develop changes (mutations) in their DNA. A cell's DNA contains the instructions that tell a cell what to do. These mutations tell the cells to grow uncontrollably and to continue living after normal cells would die. These accumulating cells can form a tumor. When left untreated, the pancreatic cancer cells can spread to nearby organs and blood vessels and to distant parts of the body.

Most pancreatic cancer begins in the cells that line the ducts of the pancreas. This type of cancer is called pancreatic adenocarcinoma or pancreatic exocrine cancer. Less frequently, cancer can form in the hormone-producing cells or the neuroendocrine cells of the pancreas. These types of cancer are called pancreatic neuroendocrine tumors, islet cell tumors or pancreatic endocrine cancer.