What is Pancreatic Cancer?

Exocrine or Endocrine – How Do They Differ
Prepared by: M.D. Anderson Cancer Center Orlando

Pancreatic cancer when derived from the exocrine cells is termed “adenocarcinoma of the pancreas”; whereas cancer derived from endocrine cells are termed “islet cell” or “endocrine tumors”. Exocrine cancers account for the majority (95%) of pancreatic cancers. Another major difference between exocrine and endocrine cancers is the malignant potential (lethality) of the tumors, exocrine cancers being much more malignant.

The pancreas is both an exocrine (external secreting) organ and an endocrine (internal secreting) organ, i.e. it has dual functionality. Exocrine organs or glands produce fluids that pass through ducts that eventually exit the body, whereas endocrine organs or glands produce fluids that enter blood vessels within the gland. The exocrine cells of the pancreas produce enzymes that are secreted into the small intestine (duodenum) to assist in the digestion of food, while the endocrine cells within the pancreas (the islets of Langerhans) produce hormones such as insulin that enter the body by way of the blood stream and assist with the metabolism of nutrients, principally glucose.

What Treatments are Available

Surgery: Pancreaticoduodenectomy (the Whipple procedure) which removes the entire pancreas as well as the majority of the duodenum is the most commonly performed cancer-directed operation for pancreatic cancer. Because of the frequent finding of inoperability when diagnosis is made of pancreatic cancer, this major operation is used in less than 10% of patients. The five-year survival rate for patients treated by pancreaticoduodenectomy in 1985 was 3%. More recent studies reveal that when the surgery is performed in an institution where the volume of surgery for pancreatic surgery is large the 5-year survival rate approaches 20%.

Non-surgical Treatment: For patients with advanced pancreatic cancer who cannot have their tumors removed surgically, the focus of treatment involves symptom prevention and control. This may involve the use of:

surgery to relieve intestinal blockage or to perform nerve blocks for pain;
radiation therapy to relieve painful disease sites; or
chemotherapy to reduce the rate of tumor growth and to prolong survival

For some patients whose tumors cannot be removed surgically, chemotherapy and radiation therapy are sometimes given together to reduce the size of the tumor.