Long-term follow-up of a large series of patients with type 1 gastric carcinoid tumors: data from a multicenter study.

Objective: To study the clinical presentation, diagnostic approach, response to treatment, and the presence of other pathologies in patients with gastric carcinoid type 1 (GC 1) tumors.
Design and Methods: Retrospective analysis of 111 patients from four institutions and a mean follow-up of 76 months.
Results: The main indications for gastroscopy were upper gastrointestinal tract symptoms. The mean number of lesions, maximum tumoral diameter, and percentage of cells expressing Ki-67 labeling index were 3.6±3.8, 8±12.1 mm and 1.9±2.4% respectively. Serum gastrin and chromogranin A (CgA) levels were elevated in 100/101 and 85/90 patients respectively. Conventional imaging studies demonstrated pathology in 9/111 patients. Scintigraphy with radiolabeled octreotide was positive in 6/60 without revealing any additional lesions. From the 59 patients who had been followed-up without any intervention, five developed tumor progression. Thirty-two patients were treated with long-acting somatostatin analogs (SSAs), leading to a significant reduction of gastrin and CgA levels, number of visible tumors, and CgA immune-reactive tumor cells in 28, 19, 27, and 23 treated patients respectively. Antrectomy and/or gastrectomy were initially performed in 20 patients and a complete response was achieved in 13 patients. The most common comorbidities were vitamin B12 deficiency, thyroiditis, and parathyroid adenomas.
Conclusions: Most GCs1 are grade 1 (82.7%) tumors presenting with stage I (73.9%) disease with no mortality after prolonged follow-up. Ocreoscan did not provide further information compared with conventional imaging techniques. Treatment with SSAs proved to be effective for the duration of administration.