Translating the immune microenvironment of thyroid cancer into clinical practice.

Thyroid cancer is an excellent model for studying tumor immune microenvironment, as it often shows local signs of an immune response. The tumor immune microenvironment of thyroid cancer is the heterogeneous histological space in which tumor cells coexist with host cells. The final composition of this cellular aggregate is associated with the clinical aggressiveness characteristics of the neoplasm. High-performance multiplex technologies suggest that specific genetic signatures of the tumor immune microenvironment may provide data for the delineation of a robust prognostic model. Several proposals integrate clinic, pathologic and immunological information in an attempt to translate the knowledge gained from molecular science into a more personalized approach for the treatment strategy of patients with thyroid cancer. In addition, the tumor immune microenvironment displays multiple molecular connections between cells, revealing complex crosstalk. This interesting network generates several molecular nodes that can be used as targets for immunotherapy. In this scenario, immunotherapy emerges as a promising weapon, mainly for patients with advanced thyroid cancer, both medullary and follicular cell-derived. In fact, although most patients with thyroid cancer have an excellent prognosis with current therapies, around 30% of cases evolve in an unfavorable way, leading to the urgent need to improve immunotherapy for high-risk patients. Preclinical and early clinical investigations are providing optimistic prospects, but more studies are needed to make immunotherapy a more viable and efficient tool for years to come.