The pancreas is a 6-inch long organ located behind the stomach in the back of the abdomen, near the gall bladder.
It contains glands that create pancreatic juices, hormones, and insulin.
Cancer can affect either the endocrine or the exocrine glands in the pancreas.
The exocrine glands produce juices, or enzymes, that enter the intestines and help digest fat, proteins, and carbohydrates. These make up most of the pancreas.
The endocrine glands are small clusters of cells known as the islets of Langerhans. They release the hormones insulin and glucagon into the bloodstream. There, they manage blood sugar levels. When they are not working properly, the result is often diabetes.
The type of cancer and the outlook for each depends on which function the cancer affects.
Type
There are two different types of pancreatic cancer, depending on whether it affects the exocrine or endocrine functions. They have different risk factors, causes, symptoms, diagnostic tests, treatments, and outlook.
Exocrine pancreatic cancer
Tumors that affect the exocrine functions are the most common type.
They can be malignant or benign. Benign tumors or cysts are are called cystadenomas. Most pancreatic tumors are malignant, or cancerous.
Different types of pancreatic cancers can affect the exocrine functions.
Types of tumor include:
- adenocarcinomas, which typically start in gland cells in the ducts of the pancreas
- acinar cell carcinoma, which starts in the pancreatic enzyme cells
- ampullary cancer, which starts where the bile duct and pancreatic duct meet the duodenum of the small intestine
- adenosquamous carcinomas
- squamous cell carcinomas
- giant cell carcinomas
Endocrine pancreatic cancer
Tumors that affect the endocrine functions of the pancreas are called neuroendocrine or islet-cell tumors. These are fairly uncommon.
The name comes from the type of hormone-producing cell where the cancer starts.
They include:
- insulinomas (insulin)
- glucagonomas (glucagon)
- gastrinomas (gastrin)
- somatostatinomas (somatostatin)
- VIPomas (vasoactive intestinal peptide or VIP)
Functioning islet cell tumors continue to make hormones. Non-functioning ones do not. Most of these tumors are benign, but non-functioning tumors are more likely to be malignant, islet-cell carcinomas.
Causes and risk factors
Scientists do not know exactly why uncontrolled cell growth happens in the pancreas, but they have identified some possible risk factors.
Genetic factors
Damage or changes in a person’s DNA can lead to damage in the genes that control cell division.
Hereditary genetic changes pass down through a family. There is evidence that pancreatic cancer can run in families.
Other genetic changes happen because of exposure to an environmental trigger, for example, tobacco.
A person with certain genetic syndromes is more likely to develop pancreatic cancer.
These include:
- hereditary breast and ovarian cancer syndrome
- melanoma
- pancreatitis
- non-polyposis colorectal cancer (Lynch syndrome)
Sex
Pancreatic cancers affect men than often than women.