Background: Normalization of gastric secretion and cure of associated upper gastrointestinal lesions by resection of gastrinoma is possible in approximately 20% of patients with Zollinger-Ellison syndrome, leaving approximately 80% dependent on medical treatment with proton pump inhibitors for acid suppression.
Methods: Lansoprazole was given for 3-48 months (median 28 months) to 26 Zollinger-Ellison syndrome patients with peptic ulcer manifestations in all and oesophagitis in 13. Starting with 60 mg/day. the dose was individualized to lower basal acid output to less than 5 mmol/h for those with intact stomachs and less than 1 mmol/h in those who had prior gastrectomy or with oesophagitis. The patients were studied every 3 months for 1 year and then every 6 months with gastric analysis (basal and maximal acid and pepsin output) and endoscopy with biopsy for enterochromaffin-like (ECL) cells.
Results: Lansoprazole inhibited basal acid output by 95%, pepsin output by 65% and remained effective at the initial mean (66 +/- 4.3 mg/day) or smaller doses (56 +/- 12 mg/day) at 48 months. Mucosal lesions healed and symptoms (ulcer-type pain, diarrhoea, heartburn, weight loss) resolved rapidly, usually within a few weeks. Serum gastrin and ECL cell populations, which were elevated before treatment, remained statistically unchanged but one of the three multiple endocrine neoplasia I (MEN-I) patients developed a small carcinoid. Of the three patients with metastatic gastrinoma at diagnosis one has died and one has progressed, while the third has had stable liver metastases for 26 years. Ulcer-type relapses occurred in three of the five post-gastrectomy patients, one with fatal jejunal ulcer perforation despite adequate acid suppression. No biochemical or clinical adverse events due to lansoprazole were encountered.
Conclusion: Lansoprazole effectively inhibits acid and pepsin secretion in Zollinger-Ellison syndrome patients without any demonstrated side-effects. Despite strict acid control, post-gastrectomy Zollinger-Ellison syndrome patients were more liable to ulcer relapse, while oesophagitis was not a marker for therapeutic difficulty.