ECL cell tumor and poorly differentiated endocrine carcinoma of the stomach: Prognostic evaluation by pathological analysis

Background & Pims: Gastric endocrine tumors show a wide spectrum of clinica l behavior, and prognostic assessement of individual tumors is difficult. T he aims of this work were to identify predictors of tumor malignancy and pa tient outcome. and to provide a rationale for treatment; guidelines. Method s: Gastric endocrine tumors (86 enterochromaffin-like cell carcinoids and 1 6 poorly differentiated carcinomas) were. investigated for 15 clinicopathol ogic variables and for expression of Ki67, P53, and BCL-2 proteins. Data we re analyzed by univariate and multivariate statistics far evidence of tumor malignancy and patient survival. Results: Histological grades 2 and 3, siz e greater than or equal to 3 cm, 9 or move mitoses, or greater than or equa l to 300 Ki67-positive cells per 10 high-power fields identified 26 of 33 ( 79%) malignant (metastatic or deeply invasive) tumors, and size <1 cm and/o r growth restricted to the mucosa characterized 46 of 69 (67%) tumors with benign behavior during a median follow-up of 39 months. Malignancy-predicti ve models were developed using angioinvasion, size, clinicopathologic type, mitotic index, and Ki67 index. The same variables, in addition to deep gas tric wall invasion and histological grade, predicted patient outcome. Concl usions: Criteria for the assessment of malignancy risk and patient outcome were developed for the different tumors, providing a basis for treatment gu idelines.