Zollinger-Ellison Syndrome

This is a unusual condition which affects the gastrointestinal system. Commonly referred to as ZES it causes tumours called gastrinoma to develop in the duodenum (the foremost segment of the small intestine) and pancreas. Gastrinoma cause excessive secretion of a hormone called gastrin, which can increase the risk of ulcers developing in the duodenum and stomach.

Zollinger-Ellison syndrome tends to affect men more often than women and it is most common among middle-aged people. Around a quarter of people who have Zollinger-Ellison syndrome also possess a genetic problem recognised as multiple endocrine neoplasia type 1. This is known to cause tumours in the parathyroid and pituitary glands. People who have MEN1 have a 20-60% chance of developing Zollinger-Ellison syndrome and children who have a parent with MEN1 have a 50% chance of inheriting the condition, which will increase their risk of suffering from ZES.

What causes Zollinger-Ellison syndrome?

Zollinger-Ellison syndrome is caused by tumours called gastrinoma which develop in the small intestine and pancreas. These tumours increase secretion of the hormone gastrin, and this causes unpleasant symptoms and the development of peptic ulcers. It is not fully understood why people with Zollinger-Ellison syndrome develop tumours. Some people also have a condition called MEN1, but this only accounts for 25% of cases. Symptoms of MEN1 include:

• Kidney stones.
• Increased levels of hormones in the blood.
• Weakened muscles.
• Diabetes.
• Weakened bones.

Signs of Zollinger-Ellison syndrome

• Abdominal pain, which may feel like heartburn (a burning sensation).
• Weight loss.
• Diarrhoea.
• Nausea.
• Vomiting.
• Gastro-oesophageal reflux.
• Gastro-intestinal bleeding (in the stomach and intestines).
• Tiredness and weakness.

Complications of Zollinger-Ellison syndrome

The major complication of ZES is developing malignant (cancerous) tumours. Some people may only have one gastrinoma, but others may have several and it is possible for tumours to spread to other parts of the body (this process is known as metastases), including the liver, spleen, bones and lymph nodes.

How is the condition diagnosed?

It is common for Zollinger-Ellison syndrome to be diagnosed as a peptic ulcer at first. If your GP deems that you possess symptoms related to Zollinger-Ellison syndrome, they will refer you to a specialist gastroenterologist for further tests. Tests carried out will include a blood test to check the presence of the hormone gastrin, in addition to a carried out to assess levels of acid in the stomach. An endoscopy may also be recommended to check for ulcers, which involves using a thin, flexible tube called an endoscope to examine the inside of the oesophagus, stomach and duodenum (the upper portion of the small intestine). A CT scan may also be ordered to find the gastrinoma and check for metastases, which is when cancer has spread to other parts of the body.

Treatment for Zollinger-Ellison syndrome

The main aim of treatment is to try and reduce the total of acid produced by the stomach. A form of medication called proton pump inhibitors is usually used to decrease acid levels, but if acute symptoms develop PPIs may be given intravenously. Examples of proton pump inhibitors include omeprazole, pantoprazole and lansoprazole.

Surgery is sometimes carried out to remove ulcers and gastrinoma. If complications such as internal bleeding arise, emergency surgery will usually be performed.

If a patient has malignant tumours, they may be advised to have chemotherapy or radiotherapy treatment to try and reduce the size of the tumour and prevent the tumours from spreading to other parts of the body.

What is the outlook for patients?

The outlook for patients with the condition largely depends on whether the gastrinoma are malignant and if they have spread to other areas of the body. Around 2/3 of people with ZES will survive at least five years after diagnosis. Among those who have gastrinoma that haven’t impacted the liver, the 5 year rate of survival is much higher; at approximately 90 percent. If tumours have impacted the liver the outlook is poor, with a 5 year survival rate of just 20 percent.

Patients who have been diagnosed with Zollinger-Ellison syndrome are encouraged to visit their doctors on regularly to allow them to monitor their progress and check for early signs that the gastrinoma are reappearing.