Zollinger-Ellison Syndrome (ZES) is a rare disorder characterized by one or more tumors in the pancreas, duodenum, or both. The tumors cause the stomach to make too much acid, leading to peptic ulcers in the duodenum. The tumors are sometimes cancerous and spread to other areas of the body.
ZES is caused by tumors called gastrinomas, which release the hormone gastrin. Normally, cells in the stomach produce and control gastrin so only the right amount is released. Gastrin travels through the bloodstream to signal other cells in the stomach to release gastric acid to help break down food. Gastrinomas release abnormal amounts of gastrin, resulting in excess gastric acid in the stomach and duodenum. The excess acid eventually causes sores called peptic ulcers to form in the lining of the duodenum.
Scientists are unsure what causes the majority of gastrinomas, which appear sporadically. About 25 percent of gastrinoma cases are caused by an inherited genetic disorder called multiple endocrine neoplasia type 1 (MEN1). MEN1 can cause a variety of hormone-releasing tumors such as prolactinomas and insulinomas.
Anyone can get ZES, but the disease is more common among men 30 to 50 years old. People with MEN1 have a 20 to 61 percent chance of developing ZES. Children who have a parent with MEN1 have a 50 percent chance of inheriting the MEN1 gene and are, therefore, also at increased risk of ZES.
ZES symptoms are similar to those of peptic ulcers and include:
- Burning abdominal pain
- Nausea and vomiting
- Weight loss
- Severe gastroesophageal reflux — a condition where gastric acid and food from the stomach backs up into the esophagus
The outcome for people with ZES largely depends on the nature and extent of the gastrinomas. About 25 percent of gastrinoma cases are considered cancerous, with an estimated 10-year survival rate of around 30 percent. The remaining cases are considered slow-growing, with an estimated 10-year survival rate of around 95 percent. If peptic ulcer symptoms are well controlled, however, most patients—even those with tumors that spread—will feel well until the late stages of the disease.
ZES is treated with medications to relieve ulcer symptoms and surgery, if appropriate, to remove tumors. Chemotherapy is sometimes used when tumors are too widespread to remove with surgery. A class of drugs called proton pump inhibitors effectively reduces gastric acid secretion in the stomach. Reducing stomach acid allows peptic ulcers to heal and relieves ZES symptoms.
The only cure for ZES is surgical removal of gastrinomas. Some gastrinomas behave like cancers and spread to other parts of the body, especially the liver and bones. Finding and removing all gastrinomas is often challenging. Gastrinomas that cannot be surgically removed are sometimes treated with chemotherapy drugs.