Objective:This study analyzes the clinicopathological features and prognostic factors of early-stage gastric mixed adenoneuroendocrine carcinoma (G-MANEC), which is an exceedingly rare malignancy, in an effort to provide evidence-based insights for clinical decision-making.Methods:A retrospective observational study was conducted using the clinical data of 36 patients with early-stage G-MANEC who underwent surgical resection at Zhongshan Hospital, Fudan University, from July 2014 to May 2022. The observed indicators included clinicopathological data and follow-up information on recurrence, metastasis, and overall survival (OS).Results:Among the 36 patients there were 21 males and 15 females, aged 32-84 (65±11) years. The most common initial symptoms were abdominal pain and distension (19/36, 52.8%), followed by incidental findings during physical examinations (7/36, 19.4%). Tumors were located in the proximal stomach in 13 cases (36.1%), the middle stomach in 4 cases (11.1%), and the distal stomach in 19 cases (52.8%). Average tumor diameter was (2.48±1.18) cm. Gross morphology included elevated type in 12 cases (33.3%), flat type in 20 cases (55.6%), and depressed type in 4 cases (11.1%). Ulceration was present in 12 cases (33.3%). There were 11 cases (30.6%) at T1a stage and 25 cases (69.4%) at T1b stage. Lymph node metastasis was positive in 10 cases (27.8%), and the differentiation grades of the adenocarcinoma component were Grade I, II, and III in 3 (8.3%), 10 (27.8%), and 23 (63.9%) cases, respectively. Furthermore, the proportion of neuroendocrine carcinoma component was ≥50% in 18 cases (50.0%) and <50% in 18 cases (50.0%). Lymphovascular or perineural invasion was present in 18 cases (50.0%). Lauren classification included mixed type in 10 cases (27.8%), intestinal type in 19 cases (52.8%), and diffuse type in 7 cases (19.4%), and chromogranin A (CgA) positivity was found in 20 cases (55.6%). Additionally, the Ki-67 index positivity was found in 26 cases (72.2%). Total gastrectomy was performed in 12 cases (33.3%) and partial gastrectomy in 24 cases (66.7%), with a median follow-up duration of 77.5 months. The 3-year and 5-year OS rates were 88.89% and 79.67%, respectively. Univariate analysis revealed that age, gross morphology, ulceration, proportion of neuroendocrine carcinoma component, lymphovascular or perineural invasion, and chromogranin A (CgA) positivity showed statistical significance in their association with OS ( P<0.10). Multivariate Cox regression analysis further identified ulceration (HR=7.74, 95%CI: 1.24-48.30, P=0.028) and CgA positivity (HR=21.76, 95%CI: 1.86-53.97, P=0.014) as independent risk factors of OS. Conclusions:Patients with early-stage G-MANEC are typically asymptomatic, and those with ulceration or positive CgA immunohistochemical staining tend to have a poor prognosis.

Objective:This study analyzes the clinicopathological features and prognostic factors of early-stage gastric mixed adenoneuroendocrine carcinoma (G-MANEC), which is an exceedingly rare malignancy, in an effort to provide evidence-based insights for clinical decision-making.Methods:A retrospective observational study was conducted using the clinical data of 36 patients with early-stage G-MANEC who underwent surgical resection at Zhongshan Hospital, Fudan University, from July 2014 to May 2022. The observed indicators included clinicopathological data and follow-up information on recurrence, metastasis, and overall survival (OS).Results:Among the 36 patients there were 21 males and 15 females, aged 32-84 (65±11) years. The most common initial symptoms were abdominal pain and distension (19/36, 52.8%), followed by incidental findings during physical examinations (7/36, 19.4%). Tumors were located in the proximal stomach in 13 cases (36.1%), the middle stomach in 4 cases (11.1%), and the distal stomach in 19 cases (52.8%). Average tumor diameter was (2.48±1.18) cm. Gross morphology included elevated type in 12 cases (33.3%), flat type in 20 cases (55.6%), and depressed type in 4 cases (11.1%). Ulceration was present in 12 cases (33.3%). There were 11 cases (30.6%) at T1a stage and 25 cases (69.4%) at T1b stage. Lymph node metastasis was positive in 10 cases (27.8%), and the differentiation grades of the adenocarcinoma component were Grade I, II, and III in 3 (8.3%), 10 (27.8%), and 23 (63.9%) cases, respectively. Furthermore, the proportion of neuroendocrine carcinoma component was ≥50% in 18 cases (50.0%) and <50% in 18 cases (50.0%). Lymphovascular or perineural invasion was present in 18 cases (50.0%). Lauren classification included mixed type in 10 cases (27.8%), intestinal type in 19 cases (52.8%), and diffuse type in 7 cases (19.4%), and chromogranin A (CgA) positivity was found in 20 cases (55.6%). Additionally, the Ki-67 index positivity was found in 26 cases (72.2%). Total gastrectomy was performed in 12 cases (33.3%) and partial gastrectomy in 24 cases (66.7%), with a median follow-up duration of 77.5 months. The 3-year and 5-year OS rates were 88.89% and 79.67%, respectively. Univariate analysis revealed that age, gross morphology, ulceration, proportion of neuroendocrine carcinoma component, lymphovascular or perineural invasion, and chromogranin A (CgA) positivity showed statistical significance in their association with OS ( P<0.10). Multivariate Cox regression analysis further identified ulceration (HR=7.74, 95%CI: 1.24-48.30, P=0.028) and CgA positivity (HR=21.76, 95%CI: 1.86-53.97, P=0.014) as independent risk factors of OS. Conclusions:Patients with early-stage G-MANEC are typically asymptomatic, and those with ulceration or positive CgA immunohistochemical staining tend to have a poor prognosis.