Clinicopathological features and survival analysis of gastric cancer patients with neuroendocrine differentiation after radical resection

Objective: To compare the clinicopathological characteristics and the prognosis of gastric adenocarcinoma patients with and without neuroendocrine differentiation (NED) after radical gastrectomy plus D2 lymph node dissection. Methods: A retrospective cohort study was performed. The inclusion criteria were as follows: (1) patients who underwent radical resection of gastric cancer plus D2 lymph node dissection and were confirmed as gastric adenocarcinoma by postoperative pathology and received immunohistochemical examination of neuroendocrine markers Syn and/or CgA; (2) patients aged 20 to 75 years with normal organ function; (3) patients who did not receive neoadjuvant chemotherapy or radiotherapy before operation; (4) patients with postoperative pathological stage I to III according to the 8th edition of tumor staging system of American Joint Committee on Cancer (AJCC); and (5) patients who completed adjuvant chemotherapy according to the postoperative pathological stage. Those who had other malignant tumors in the past 5 years and who could not be followed up according to the required rules were excluded. According to the above criteria, the clinicopathological characteristics of gastric cancer patients who underwent radical resection plus D2 lymph node dissection in Zhongshan Hospital of Fudan University from January 2010 to June 2017 were collected and compared. All patients were followed up till June 2020. The disease-free survival (DFS) and overall survival (OS) between the patients with and without NED were compared, and the effect of NED on the prognosis was corrected by Cox proportional hazards model. The propensity score matching method was used for sensitivity analysis. Results: A total of 539 patients were enrolled in this study, including 35 with NED and 504 without NED. Compared with the patients without NED, the patients with NED were older [(65.0±7.5) years vs. (54.5±11.3) years, t=-7.681, P 0.05). Sensitivity analysis showed that there was no significant difference in DFS and OS between the two groups after propensity score matching. Conclusion: Compared with patients without NED, patients with NED were older at onset, had a higher proportion of proximal gastrectomy, intestinal-type, and later diagnostic stage, but the survival prognosis had no significant difference with that of patients without NED.