Abstract
Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the head and neck. The current treatment principle is based on radical surgery, supplemented by radiotherapy and chemotherapy. However, the 5-year survival rate of patients is still around 50%. Therefore, further research on the molecular mechanism of OSCC development is needed to find out more effective treatment methods. In this study, the expression of E-cadherin, vimentin, CD206, PD-1 and PD-L1 in pathological sections of 45 patients with oral squamous cell carcinoma was quantified by immunohistochemistry. The results showed that the expression levels of vimentin, CD206 and PD-L1 were all significantly different from overall survival. At the same time, COX multivariate analysis showed that CD206, the marker of M2 macrophages,was an independent risk factor for poor prognosis in OSCC. Moreover, correlation analysis showed that the expression of E-cadherin was negatively correlated with the expression levels of vimentin, CD206 and PD-L1. The expression of vimentin was positively correlated with PD-1 and PD-L1. Therefore, the statistical data of immunohistochemical experiments in this study first showed that M2 macrophage was an independent risk factor for poor prognosis in OSCC, and was also closely related to poor overall survival. Second, it may affect the occurrence and development of OSCC tumors by inducing the occurrence of EMT in OSCC tumor cells. Third, PD-L1 has an adverse effect on the prognosis of OSCC, and it is significantly correlated with the expression levels of CD206, E-cad and vimentin. However, whether the PD-1/PD-L1 pathway can affect the occurrence and development of OSCC through M2 macrophages still needs to be further studied.