Mixed adenoneuroendocrine carcinomas of stomach and ampulla of vater after curative-intent resection: a single center cases series.

<bold>Background: </bold>Mixed adenoneuroendocrine carcinoma is a rare clinical manifestation, especially in the gastric and ampullary. The purpose of this study was to investigate the clinicopathological features and prognosis of mixed adenoneuroendocrine carcinoma in the gastric and ampullary and summarize related treatment suggestions.<bold>Methods: </bold>In all, 32 cases of mixed adenoneuroendocrine carcinoma in the gastric and ampullary that were diagnosed from resected specimens were analyzed from 2009 to 2015. The corresponding demographic, clinicopathological and survival data were retrospectively reviewed.<bold>Results: </bold>The 1-year, 3-year and 5-year survival rates were 78.1%, 28.1 and 9.4%, respectively, and the median overall survival was 28.0 months. In all, 75.0% (24/32) had lymph node metastasis at the time of initial diagnosis. A multivariate analysis revealed that TNM stage (HR 6.444 95%CI 1.477-28.121 P = 0.013), lymph nodes metastasis (HR10.617 95%CI 1.409-79.997 P = 0.022), vascular invasion (HR 5.855 95%CI 1.719-19.940 P = 0.005), grade of the adenocarcinoma component (HR 3.876 95%CI 1.451-10.357 P = 0.007) and CD56 positivity (HR 0.265 95%CI 0.100-0.705 P = 0.008) were independent predictors of overall survival.<bold>Conclusions: </bold>Mixed adenoneuroendocrine carcinoma is an aggressive clinical entity with a poor prognosis. Taking both the neuroendocrine component and the adenocarcinoma component into consideration of optimal treatment is strongly recommended. [ABSTRACT FROM AUTHOR]