ESMO Asia Virtual Congress 2020

Abstract 187P

Background

Few reports address the impact of surgery on the prognosis of rare and heterogeneous gastric neuroendocrine carcinoma (G-NEC). This study analyzed the influence of surgical treatments on prognosis to provide a personalized surgical treatment strategy for G-NEC patients.

Methods

The clinicopathological data of 964 G-NEC patients from 24 Chinese hospitals were analyzed. Cox regression analyses were used to analyze the prognostic factors affecting survival and recurrence, respectively.

Results

Cox analysis revealed that in stage I-II but not stage III gastric neuroendocrine carcinoma/mixed adenoneuroendocrine carcinoma (NEC/MANEC) patients, D2 (extended) lymph node dissection (ELND) was an independent protective factor for OS and DFS (p<0.05; p<0.05). In stage I-II, 3-year OS and DFS increased with more of LNs dissected (p<0.05), while in stage III patients undergoing ELND, the 3-year OS and DFS was similar to patients undergoing D1+ (limited) lymph node dissection (LLND) (p>0.05). Furthermore, among patients with stage III disease, the incidence of complications after ELND was significantly greater than that after LLND (28.4% vs. 12.1%, p < 0.001), especially severe complications (Clavien-Dindo grade III-V). For patients with stage I-II disease, ELLN not only brings lower overall recurrence rate (ELND vs. LLND = 16.9% vs 27.6%, p = 0.018) but also reduced the risk of regional LN and distant LN recurrence (all p < 0.05).

Conclusions

ELND may lead to enhanced long-term survival for stage I and II but not stage III NEC/MANEC patients. Our results in multicenter patients do not support the routine use of ELND in stage III NEC/MANEC patients.