Clinical Significance of Polo-Like Kinase 4 as a Marker for Advanced Tumor Stage and Dismal Prognosis in Patients With Surgical Gastric Cancer

OBJECTIVE: This study aimed to investigate the correlation of polo-like kinase 4 with clinicopathological features and survival profiles in patients with gastric cancer. METHODS: This retrospective study was conducted based on the clinical data from 289 eligible patients with gastric cancer who received resection. Polo-like kinase 4 expression in adjacent tissue and tumor tissue was determined by immunohistochemical assay and semiquantified scoring method using immunohistochemical score by staining intensity score multiplying staining density score. Based on the total immunohistochemical score (ranged from 0 to 12), the polo-like kinase 4 expression was classified as low expression (immunohistochemical: 0-3) and high expression (immunohistochemical: 4-12); furthermore, high expression was divided into high+ expression (immunohistochemical: 4-6), high++ expression (immunohistochemical: 7-9), and high+++ expression (immunohistochemical: 10-12). RESULTS: Polo-like kinase 4 expression was elevated in tumor tissue compared with adjacent tissue. Tumor polo-like kinase 4 high expression correlated with increased T stage and Tumor, Node, Metastasis (TNM) stage, while, it did not correlate with age, gender, current smoke, current drink, chronic complications, Helicobacter pylori infection, tumor location, pathological grade, or N stage. Besides, higher tumor polo-like kinase 4 expression correlated with shorter disease-free survival and overall survival. Subsequently, multivariate Cox proportional hazards regression analysis showed that higher tumor polo-like kinase 4 expression was an independent predictive factor for worse disease-free survival but not for overall survival. CONCLUSION: Polo-like kinase 4 possesses the clinical significance as a biomarker for aiding prognostication and facilitating postoperative tumor management in patients with gastric cancer.