Objective To investigate the expression of KIF3A in different gastric mucosal lesions and corresponding metastatic lymph nodes, and to explore its relationship with the occurrence, clinicopathologic characteristics, metastasis and prognosis of gastric adenocarcinoma.

Methods The expression of KIF3A was detected immunohistochemically in different gastric mucosal lesions and corresponding metastatic lymph nodes. SPSS23.0 software package was used for statistical analysis.

Results The expression of KIF3A was higher in gastric adenocarcinoma tissues than that in corresponding adjacent tissues(P < 0.01), and it was also higher in metastatic lymph nodes than that in corresponding primary lesions(P < 0.01). The expression of KIF3A both in low- and high-grade intraepithelial neoplasia were significantly higher than that in chronic gastritis(P < 0.01). In addition, KIF3A expression in advanced gastric adenocarcinoma was correlated with TNM grade, lymph node metastasis and vascular invasion(P < 0.05). Patients with high expression of KIF3A had shorter overall survival and disease-free survival than those with low expression of KIF3A(P < 0.01), and patients with both cytoplasm and nuclear expression of KIF3A had shorter overall survival than those with exclusively cytoplasmic distribution(P < 0.05). COX multivariate analysis showed that high expression of KIF3A was an independent risk factor for overall survival and disease-free survival of patients with gastric adenocarcinoma(P < 0.05).

Conclusion KIF3A may be correlated with intraepithelial neoplasia of gastric mucosa. Both the up-regulation of KIF3A and nuclear expression of KIF3A may be related to poor prognosis of advanced gastric adenocarcinoma patients. KIF3A may be an independent prognostic factor for advanced gastric adenocarcinoma.