THERAPY OF ENDOCRINE DISEASE Immunotherapy of advanced thyroid cancer: from bench to bedside.

Immunotherapy has arisen in use in the field of oncology with seven immune checkpoint inhibitors approved for the treatment of a variety of cancer histologies. Depending on the cancer type, the success rate might be different, but in average it is about 20%, with some cases showing a durable response, lasting also after the interruption of the treatment, with a clear benefit on OS. The development of an efficacious cure for advanced thyroid carcinomas is still an unmet need and immunotherapy represents an interesting alternative option also for this cancer.

The Aryl Hydrocarbon Receptor Is Expressed in Thyroid Carcinoma and Appears to Mediate Epithelial-Mesenchymal-Transition.

Aryl hydrocarbon receptor (AhR) is expected to promote initiation, progression and invasion of cancer cells regulating proliferation, differentiation, gene expression, inflammation, cell motility and migration. Furthermore, an immunosuppressant function of AhR has been recognized. This study evaluated AhR expression and its role in thyroid cancer progression.

Immune Profiling of Thyroid Carcinomas Suggests the Existence of Two Major Phenotypes: An ATC-Like and a PDTC-Like.

Objectives: The understanding of the mechanisms underlying thyroid cancer immune escape can lead to the identification of new molecular targets and/or efficacy biomarkers. For this purpose, we performed immune expression profiling in thyroid cancers to obtain a comprehensive view on immune mechanisms activated during cancer progression.

Methods: The study was conducted retrospectively in 25 papillary thyroid carcinomas (PTCs), 14 poorly differentiated thyroid carcinomas (PDTC), 13 anaplastic thyroid carcinomas (ATCs), and 7 normal thyroid (NT) tissue samples.

Signal Transducer and Activator of Transcription 1 Plays a Pivotal Role in RET/PTC3 Oncogene-induced Expression of Indoleamine 2,3-Dioxygenase 1.

Indoleamine 2,3-dioxygenase 1 (IDO1) is a single chain oxidoreductase that catalyzes tryptophan degradation to kynurenine. In cancer, it exerts an immunosuppressive function as part of an acquired mechanism of immune escape. Recently, we demonstrated that IDO1 expression is significantly higher in all thyroid cancer histotypes compared with normal thyroid and that its expression levels correlate with T regulatory (Treg) lymphocyte densities in the tumor microenvironment.