Treatment of gastric neuroendocrine tumors - The necessity of a type-adapted treatment

Background: Gastric neuroendocrine (or gastric carcinoid) tumors have recen tly been classified into 3 types that differ in biological behavior and pro gnosis. Although the necessity of type-adapted treatment is widely accepted , it seems inconsistently used in daily practice. Hypothesis: Diagnostic differentiation into various biological types is nec essary for an adequate treatment of gastric neuroendocrine tumors. Design: Retrospective study. Setting: University hospital department of surgery. Patients: Twenty-seven patients with a histologically verified gastric neur oendocrine tumor. Main Outcome Measures: A univariate analysis of survival rates with respect to tumor type, tumor biological parameters, and treatment performed was ac complished by applying the Kaplan-Meier estimation method. The log-rank tes t was used to evaluate the level of significance. Results: The 16 type 1 (59%) and 11 type 3 (41%) gastric neuroendocrine tum ors differ in tumor size, histopathologic characteristics, and biological b ehavior. Nine (56%) of 16 type 1 gastric neuroendocrine tumors were treated by local excision, 8 of these (89%) had persistent atrophic gastropathy du ring the follow-up period. Five-year cumulative survival of patients with t ype 1 gastric neuroendocrine tumor was 100% without any progression into ma lignant phenotype. In contrast, 4 (44%) of 9 locally advanced type 3 gastri c neuroendocrine tumors were treated radically by extended resection with a 5-year cumulative survival of 75%. Conclusions: Differentiation into 3 biologically distinct tumor types for g astric neuroendocrine tumors is important with respect to therapeutic strat egy and prognostic consideration. Correct diagnosis is attainable by using endoscopy, histopathologic characteristics, and laboratory chemical analysi s and should precede any treatment. Extended radical surgery of high-risk t ype 3 tumors is indicated when definitive healing is achievable, whereas ty pe 1 tumors are best treated by endoscopic removal and long-term follow-up.