What are gastrointestinal neuroendocrine tumors?

Gastrointestinal (GI) neuroendocrine tumors are a rare type of cancer that grows in the lining of the GI tract. They are also called GI carcinoid tumors. These tumors develop from neuroendocrine cells, a type of cell that makes hormones that support certain bodily functions. Neuroendocrine cells are most common in the GI tract, where they make hormones that help control digestion.  

Most GI neuroendocrine tumors begin in the small intestine, appendix, or rectum. They usually grow slowly and can produce hormones that are released into the body. In some cases, these hormones can cause symptoms. If the tumor spreads to the liver, it can cause carcinoid syndrome, a condition that causes specific symptoms and other physical problems.

What are the symptoms of gastrointestinal neuroendocrine tumors?

Some GI neuroendocrine tumors may not cause any symptoms. If the tumors do cause symptoms, they may include:

  • Abdominal pain
  • Constipation
  • Diarrhea
  • Nausea or vomiting
  • Extreme tiredness
  • Weight loss
  • Pain in the rectum
  • Blood in the stool

How are gastrointestinal neuroendocrine tumors treated?

Treatment for GI neuroendocrine tumors depends on where the tumor is located and if it has spread to other parts of the body. Treatment options may include:

  • Surgery to remove the tumor
  • Chemotherapy may be used if the cancer has spread to other parts of the body or if the tumor is causing severe symptoms
  • Radiation therapy may be used after surgery or if surgery is not an option
  • Targeted therapy to help kill cancer cells
  • Hormone therapy to help slow the growth of neuroendocrine cells

What are the risk factors for gastrointestinal neuroendocrine tumors?

You may be more likely to develop a GI neuroendocrine tumor if:

  • Someone in your family has neurofibromatosis type 1 (NF1)
  • Someone in your family has multiple endocrine neoplasia type 1 (MEN1)
  • You have a condition that affects the amount of stomach acid your stomach makes, such as Zollinger-Ellison syndrome or atrophic gastritis
  • A family history of tuberous sclerosis complex or von Hippel Lindau disease