Gastrinomas are rare tumors forming in the pancreas or duodenum, which is the first part of the small intestine. These growths can form as a single tumor or group of tumors. They begin in the cells that produce gastrin, which is a hormone responsible for secreting gastric acid. If you have a gastrinoma, your body secretes large amounts of gastrin, resulting in a higher level of stomach acid. This higher level can cause the formation of ulcers in your stomach and small bowel.
Gastrinomas can be either benign or malignant. More than 60 percent of gastrinomas are cancerous, according to the Center for Pancreatic and Biliary Diseases.
Because gastrinomas cause an increase in stomach acid production, the symptoms are similar to those of peptic ulcers. Some people live with symptoms for several years before their doctor makes a diagnosis.
Symptoms of a gastrinoma include:
- stomach pain
- indigestion or heartburn
- weight loss
- poor appetite
Even though ulcers can occur with tumors, having an ulcer doesn’t mean you have a tumor. Your doctor, however, may check for a gastrinoma if you have a persistent ulcer and one of the following conditions:
- intestinal perforation and bleeding
- high calcium levels
- a family history of gastrinoma
- excessive stomach acid that doesn’t improve with treatment
Gastrinomas are the uncontrolled division of cells that produce gastrin. The exact cause of this condition is unknown, although there may be a genetic link.
Gastrinomas can develop sporadically for unknown reasons. But approximately 25 to 30 percent of gastrinomas are associated with an inherited genetic disorder called multiple endocrine neoplasia type 1 (MEN1), says the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD).
This hereditary disorder is characterized by the development of tumors in hormone-producing glands. Other symptoms of MEN1 may include higher hormone levels, kidney stones, diabetes, muscle weakness, and fractures.
Your doctor may recommend testing if you have ulcers that don’t respond to treatment. Diagnostic tests to confirm gastrinoma include:
Secretin test/fasting serum gastrin
This test diagnoses problems with the pancreas by measuring its ability to respond to the hormone secretin. During this test, your doctor injects the hormone into your bloodstream, and then monitors your body’s response. Your doctor checks to see whether your gastrin level increases after the injection.
Gastric pH test
This test uses an endoscopy to assess the amount of gastric acid in your stomach. Higher levels of both gastrin and stomach acid may indicate a gastrinoma.
Your doctor may order a CT scan or MRI to determine the location of the tumor and assess whether the tumor has spread to other organs. Gastrinoma tumors or lesions can be small, so these imaging tests may not produce an image. In this case, your doctor may complete an endoscopic ultrasound. For this procedure, your doctor inserts a tube with an attached camera down your throat to look for tumors in your stomach or small intestines.
If your doctor discovers a tumor, the next step is a biopsy. Your doctor removes a sample from the tumor, and then sends this sample to a lab for testing.
The location of tumors, and whether they’ve spread to other parts of the body, determines how your doctor treats gastrinoma. Surgery is the primary treatment, and the objective of surgery is to remove cancer from the body and cure the disease.
The procedure your doctor recommends is also based on the location of the tumor. Surgical options may include:
- removal of the entire tumor
- removal of the head of the pancreas or the tail of the pancreas
- small bowel resection (removal of part of the small bowel and the tumor)
- surgery to remove tumors that have spread to other organs, such as the lymph nodes or liver
Risks associated with surgery include infection, pain, and blood loss. Talk to your doctor to understand your risks.
Sometimes, surgery isn’t an option, or the cancer spreads and becomes incurable. If you develop secondary liver cancer from gastrinoma, treatment options include:
- radiofrequency ablation (uses heat to kill cancer cells)
- transarterial chemoembolization (injects chemotherapy directly into the tumor)
- selective internal radiotherapy (a therapy that targets the blood supply to the liver)
Other treatments for gastrinomas include:
- chemotherapy (kills cancer cells that can’t be removed surgically)
- proton-pump inhibitors (reduce the production of stomach acid)
Gastrinomas can worsen and lead to other problems when left untreated. You may develop additional ulcers in your stomach or small intestines, and there’s the risk of small intestine perforation. This is when a hole forms in the wall of your gastrointestinal tract.
Gastrinomas also cause poor pancreatic function in some people. If your pancreas can’t properly produce enzymes and hormones, your body may have difficulty digesting food.
There is a good prognosis when surgery is possible and the disease has not spread to other organs. With the tumor removed from the body, it’s possible to live a long, active life. But even after surgery, follow up with your doctor periodically to check for the presence of new tumors.
It’s possible to treat gastrinomas that spread to other organs, yet some of these tumors may be incurable. If so, treatment can help control symptoms and extend your life.