Tumor Microenvironment in Thymic Epithelial Tumors: A Narrative Review

Simple Summary The tumor microenvironment (TME) is defined as the environment surrounding a tumor. There is a close, dynamic relation and interaction between the tumor and its neighboring microenvironment. There are some particularities of the thymus itself and of the TME of thymic epithelial tumors that hinder the routine use of targeted therapies, including immune checkpoint inhibitors. The understanding of the unique characteristics of the TME of thymic epithelial tumors could possibly result in the development of novel promising therapies. The tumor microenvironment (TME) is a complex and constantly changing entity. The TME consists of stromal cells, fibroblasts, endothelial cells, and innate and adaptive immune cells. Cancer development and progression occurs through this interplay between the tumor and the adjacent stroma. Cancer cells are capable of modifying their microenvironment by secreting various message-carrying molecules, such as cytokines, chemokines, and other factors. This action causes a reprogramming of the neighboring cells, which are enabled to play a crucial role in tumor survival and progression. The study of TME has many clinical implications in terms of cancer therapeutics because many new drugs, such as antibodies, kinase inhibitors, and liposome formulations that can encapsulate anti-cancer drugs, can be developed. Although chemotherapy is considered the standard of treatment for advanced disease, recent research has brought to light immunotherapy as a possible systemic alternative. However, the complex structure and function of the thymus hinders its routine use in clinical practice. The aim of this review paper is to discuss the recent advances in the investigation of the unique characteristics of the TME of thymic epithelial tumors that could possibly lead to the development of novel promising therapies.

Automated summary

The tumor microenvironment (TME) consists of various cells, including cancer cells that can modify the environment through secretion of molecules, impacting tumor development and progression. Studying the characteristics of TME helps in the development of new cancer therapies.