Neuroendocrine tumors, which may be either benign (non-cancerous) or malignant (cancer), may not always be pancreatic cancer, which is always malignant.
A neuroendocrine tumor may not always be pancreatic cancer. It originates from specialized neuroendocrine cells present in the body. A neuroendocrine tumor is most commonly found in the intestine but is also found in other organs, including the pancreas and lungs.
Pancreatic cancer is always malignant while pancreatic neuroendocrine tumors may be benign (or noncancerous) or malignant (cancer). Pancreatic endocrine cancer or islet cell carcinoma is one example of a neuroendocrine tumor.
What exactly is a pancreatic neuroendocrine tumor?
If a person is diagnosed with pancreatic cancer, it is important to know which type of cancer it is: neuroendocrine cancer or exocrine cancer. These two types of cancer differ from each other in their signs and symptoms, causes, diagnosis, and treatments.
The pancreatic neuroendocrine tumor arises from the hormone-producing cells, also called islet cells, of the pancreas, whereas pancreatic exocrine cancer originates from pancreatic cells that produce enzymes for digestion.
Pancreatic neuroendocrine tumors are much less common than pancreatic exocrine tumors and carry better chances of survival.
What causes a pancreatic neuroendocrine tumor?
What exactly causes most pancreatic neuroendocrine tumors is still unclear.
Pancreatic neuroendocrine tumors occur when the islet cells develop changes (mutations) in their DNA. This causes the islet cells to multiply and grow uncontrollably. Thus, these abnormal cells accumulate to form a benign or harmful (malignant) tumor called a pancreatic neuroendocrine tumor.
The mutations can be inherited or acquired. The inherited mutations are the genetic mutations transferred from the parents to the child. The acquired mutations are random mutations that develop on exposure to cancer-causing chemicals, such as tobacco smoke.
Sometimes, the inherited genes are part of inherited syndromes that increase the risk of pancreatic neuroendocrine tumors. These inherited syndromes include:
- Multiple endocrine neoplasias, type I syndrome
- Von Hippel-Lindau disease
- Von Recklinghausen's disease (neurofibromatosis I)
- Tuberous sclerosis
How is pancreatic neuroendocrine tumor diagnosed?
To diagnose a pancreatic neuroendocrine tumor, doctors will analyze the patient’s medical history and look for the signs and symptoms. They may order one or more of the tests and procedures that include:
- Blood tests. Blood tests that look for the levels of certain gastrointestinal or pancreatic hormones (such as insulin, gastrin) point toward the subtype of pancreatic neuroendocrine tumor.
- Urine tests. When the body processes hormones, some breakdown products get excreted through the urine. Urine tests to diagnose neuroendocrine tumors will look at these breakdown products in the urine.
- Imaging tests. Imaging tests help the doctor look for structural problems and other abnormalities, such as extra growths in the pancreas. These may include ultrasound, computed tomography, and magnetic resonance imaging. A substance called a radioactive tracer may be injected into the body that helps highlight the problematic areas in the body.
Other tests and procedures
- Endoscopic biopsy (using endoscopic ultrasound to get images of the pancreas and remove a small piece from the pancreas to examine it under a microscope)
- Surgical biopsy (surgery via the abdomen to collect a sample of cells for testing)
How is pancreatic neuroendocrine tumor treated?
Treatment for a pancreatic neuroendocrine tumor varies and is based on:
- The types of cells
- The extent of cancer
- The characteristics of cancer
- The patient’s preferences
- The patient’s overall health
Treatment options may include:
- Distal pancreatectomy: Doctors remove the tumor in the tail of the pancreas by removing the entire tail.
- Whipple procedure (pancreaticoduodenectomy): When cancer affects the head of the pancreas, doctors remove cancer and a part or most of the pancreas.
- Peptide receptor radionuclide therapy (PRRT): PRRT involves injecting a combination of a drug that targets cancer cells with a small amount of a radioactive substance into a vein. The combination is delivered over weeks or months that destroys the pancreatic tumor.
- Targeted therapy: This uses medications that target specific genes and proteins that are involved in the growth and survival of cancer cells. It is used to treat certain advanced or pancreatic neuroendocrine tumors that keep coming back.
- Radiofrequency ablation: This involves killing cancer cells by applying energy waves that heat them.
- Chemotherapy: Chemotherapy treatment involves using chemicals (drugs) to kill cancer cells.