Abstract
OBJECTIVE: This study aims to examine the expression patterns of chemokine CCL2 in oral squamous cell carcinoma tissues, adjacent tissues and tumor microenvironment, including the examine of the paraffin block and the examination of the peripheral blood. It seeks to analyze the associations between CCL2 expression and clinical features, pathological characteristics, and prognosis, as well as assess its potential as a prognostic biomarker. METHODS: We enrolled 119 patients with OSCC in this study. Immunohistochemistry detected CCL2 protein expression in cancerous and adjacent tissues. We used enzyme-linked immunosorbent assay (ELISA) to quantify serum CCL2 concentrations in patients both pre- and post-surgery. The chi-square test analyzed the correlation between CCL2 expression and clinical characteristics. We applied the paired t-test to compare pre- and post-surgery CCL2 changes. The Kaplan-Meier method evaluated CCL2's impact on overall survival (OS) and disease-free survival (DFS) of patients. RESULTS: Immunohistochemical analysis revealed that CCL2 expression was significantly elevated in OSCC tissues compared to adjacent normal tissues (P < 0.05). High CCL2 expression correlated strongly with advanced T stage (P = 0.002), clinical stage (P = 0.001), and lymph node metastasis (P = 0.001). Survival analysis showed that patients with elevated CCL2 levels in tumor tissues had significantly shorter overall survival (P < 0.001). Serological analysis indicated a significant overall decrease in postoperative serum CCL2 levels (P = 0.002); however, this decrease was not pronounced in patients with advanced stages (T3-4, stage III-IV) or recurrence. A combined analysis revealed that patients with high CCL2 expression in OSCC and increased postoperative serum CCL2 had the poorest disease-free and overall survival (P < 0.05). Conversely, patients with high CCL2 expression in OSCC and decreased postoperative serum CCL2 exhibited the best disease-free and overall survival (P < 0.05). CONCLUSION: The expression level of chemokine CCL2 in oral squamous cell carcinoma was significantly correlated with strong tumor invasiveness and poor prognosis. Persistently high CCL2 expression after surgery indicated a high risk of recurrence and metastasis, as well as poor prognosis. Dynamic monitoring of serum CCL2 levels is expected to become a biomarker for evaluating surgical efficacy and predicting recurrence risk. The CCL2/CCR2 signaling axis offers a new research direction for treating oral squamous cell carcinoma.