Background: To better understand gastric cancer occurrence and prognosis, we explored the expression of molecules in the CD40 pathway and their correlation with gastric cancer prognosis. Patients and Methods: We measured the expression of CD40, VEGF, AKT, PI3K, and S100 in gastric cancer tissues and adjacent normal tissues from 128 patients by immunohistochemistry. Results: The expression of CD40, VEGF, AKT, and PI3K were significantly higher in tumor tissue than in normal tissue, while S100 expression in dendritic cells (DC) was lower. Expression of CD40, VEGF, AKT, and PI3K significantly increased with T stage, while S100 expression decreased with T stage. Lymph node metastasis was associated with low or negative S100 expression. PI3K expression increased with clinical stage, while negative S100 expression was associated with higher clinical stages. Multivariate analysis did not indicate significant associations between any of these markers and recurrence or mortality. Conclusion: The correlation between T stage of gastric cancer and the higher expression of CD40, VEGF, AKT, and PI3K, along with lower S100 expression in DC, may provide insights into future targets for more effective immunotherapy for cancer.