Immune Microenvironment in Oral Potentially Malignant Disorders and Oral Cancer: A Narrative Review

Multiple studies have investigated the impact of the tumor immune microenvironment (TIME) on oral squamous cell carcinoma (OSCC), with most focusing on three key cellular components: lymphocytes, macrophages, and neutrophils, as well as the molecular mechanisms underlying inflammation-mediated OSCC invasion. Although the specific roles of each cell type vary depending on their subtypes and the characteristics of OSCC, several consistent patterns have been identified. TIME plays a critical role at every stage of OSCC progression, from tumor initiation and growth to invasion and metastasis. Understanding the communication signals-the language-between tumor cells and the TIME, encoded through various proteins secreted by immune cells, is essential for controlling tumor progression and developing effective treatments for OSCC. This review provides an overview of how TIME influences the progression of the Oral Potentially Malignant Disorders (OPMDs) to OSCC as well as OSCC's invasion, focusing on the contributions of various immune cells within the TIME. Additionally, we discuss recent advances in immunotherapy for OSCC, highlighting strategies to enhance immune responses and improve treatment outcomes.