Clinical Review
Common Variable Immunodeficiency: A Clinical Overview
Because it tends to manifest as recurrent or recalcitrant infections, common variable immunodeficiency (CVID) is often overlooked as a diagnosis....
MANAGEMENT
Once ZES has been diagnosed, the specialist will refer the patient for surgical opinion. The main objectives of surgery are to determine whether the tumor is malignant via biopsy, and to resect the tumor to suppress the acid hypersecretion, if indicated in the absence of liver metastasis and large pancreatic tumor size. Medical management should begin immediately to prevent any further damage from prolonged gastric hypersecretion.1
Pharmacologic options include PPIs, H2-receptor antagonists, and somatostatin analogues; PPIs are considered firstline therapy. Many patients with ZES require a higher dosage than is needed with typical GERD (60-100 mg/d vs 20-40 mg/d). Somatostatin analogues can be used in conjunction with PPIs and have been shown to inhibit tumor growth in patients with malignant ZES.1
Once a ZES diagnosis has been made, the tumor(s) resected (if appropriate), and vagotomy considered or performed, patients will need routine follow-up with their gastroenterologist and their primary care provider, who can manage medications and recommend any lifestyle changes.5
PROGNOSIS
The most important prognostic factor of patients with ZES is whether the gastrinoma is benign or malignant. There are two patterns: aggressive disease (25%) and nonaggressive disease (75%).5 At diagnosis, 40% to 70% of patients with sporadic ZES present with lymph node metastases, and 20% to 40% present with liver metastases. Patients with liver metastases have a 10-year survival rate of 30%, compared to a 15-year survival rate of 83% in patients without liver metastases.11,12
Along with the tumor itself, another prognostic factor to consider is the FSG level at diagnosis. Patients with higher FSG levels have decreased five- and 10-year survival rates compared to patients with lower FSG values. The 10-year survival rate for patients with a lower FSG value (0-499 pg/mL) is 86%, while the 10-year survival rate for those with a greater FSG value (> 1,000 pg/mL) is 73%.11,12 Overall, the prognosis is good for patients with ZES. The 10-year survival rate is high, and management is possible with medications and surgical resection of the gastrinoma.
PATIENT EDUCATION
Once patients are diagnosed, treatment with PPIs is typically lifelong unless they are considered cured by surgical resection. Patients need to understand that compliance is necessary to properly manage symptoms; certain foods, alcohol, and tobacco can affect the condition, and lifestyle modifications should be made, as they would with typical GERD or peptic ulcer disease.
CONCLUSION
ZES is frequently overlooked, and patients often continue to experience unresolved symptoms related to hypergastrinemia. Due to its complexity and ability to mimic other disorders—as well as the implications of duodenal versus pancreatic location, and other disorders of the kidney or endocrine system suggestive of MEN1—ZES should be ruled out in any patient with unexplained persistent GERD, peptic ulcer disease, elevated FSG, chronic diarrhea, and/or abdominal pain.5
The gastrinoma itself is a well-differentiated and slow-growing tumor in the majority of cases, making the prognosis for ZES favorable for long-term survival. Proper pharmacologic management is instrumental for controlling symptoms and decreasing acid production. Surgical resection offers patients the best chance for a complete cure. Clinicians and patients should be well educated about ZES in order to successfully manage the disorder.