This study aims to determine prognostic indicators of synaptophysin (SYN) positive gastric cancer with neuroendocrine type by analyzing differences in serological indicators and survival between SYN‐positive and SYN‐negative gastric cancer patients and to provide a theoretical basis for the prognosis of patients.

The medical records of 1298 gastric cancer patients who had received surgical treatment between January 2019 and December 2021 at The First Medical Center of Chinese PLA General Hospital were assessed, and 59 patients were enrolled in this study, to analyze serological indices and survival differences between patients with SYN‐positive and SYN‐negative gastric cancer.

There were statistically significant differences between the expression of SYN and genetic history, tumor differentiation degree, and Lauren's typing (p = 0.036, 0.040, and 0.017, respectively). The level of neuron‐specific enolase in SYN‐positive patients was higher than that in SYN‐negative patients (p = 0.027). The level of hemoglobin (Hb) and mean corpuscular hemoglobin (MCH) was lower in SYN‐positive patients when compared with SYN‐negative patients (p = 0.023 and 0.019, respectively). The survival time of SYN‐positive gastric cancer patients was statistically significantly different from that of SYN‐negative gastric cancer patients (p = 0.0255).

SYN expression in patients with gastric cancer is correlated with the degree of differentiation and Lauren's typing. The prognosis of SYN‐positive gastric cancer patients is worse than that of SYN‐negative patients.