Very low expression of PD-L1 in medullary thyroid carcinoma

Bibliographic Details
Title: Very low expression of PD-L1 in medullary thyroid carcinoma
Authors: Caterina Rebecchini, Laurence de Leval, Massimo Bongiovanni, Chiara Saglietti, Gerasimos P. Sykiotis, Laura Marino, Jean-Luc Bulliard
Source: Endocrine-Related Cancer
Endocrine-related cancer, vol. 24, no. 6, pp. L35-L38
Publisher Information: Bioscientifica Ltd, 2017.
Publication Year: 2017
Subject Terms: Research Letter, Cancer Research, Endocrinology, Oncology, Endocrinology, Diabetes and Metabolism, B7-H1 Antigen, Immunotherapy, medicine.medical_treatment, medicine, business.industry, business, Thyroid carcinoma, Cancer research, Medullary cavity, PD-L1, biology.protein, biology, Carcinoma, medicine.disease, Neuroendocrine therapy, Adult, Aged, B7-H1 Antigen/antagonists & inhibitors, B7-H1 Antigen/biosynthesis, B7-H1 Antigen/immunology, Carcinoma, Neuroendocrine/immunology, Carcinoma, Neuroendocrine/metabolism, Carcinoma, Neuroendocrine/pathology, Carcinoma, Neuroendocrine/therapy, Female, Humans, Male, Middle Aged, Thyroid Neoplasms/immunology, Thyroid Neoplasms/metabolism, Thyroid Neoplasms/pathology, Thyroid Neoplasms/therapy
Description: Monoclonal antibodies that inhibit the interaction between PD1 and PD-L1 are approved for clinical use in several cancer types, and they are also in clinical trials for additional indications, including thyroid carcinomas. A few papers have reported on PD-L1 expression in thyroid carcinomas, including a recent large study by Ahn et al. in Endocrine-Related Cancer using tissue microarrays on differentiated and anaplastic thyroid carcinoma. However, the expression of PD-L1 in medullary thyroid carcinoma (MTC) has not been reported so far, even though ongoing clinical studies aim to test the effectiveness of checkpoint inhibitors in this rare histotype as well. We thus assessed PD-L1 expression in both tumor cells and tumor-infiltrating immune cells in a series of 16 MTC cases at a tertiary center. Tumor cells were positive in only one case, which had 5% positive cells. 1% and 2% of the inflammatory cells were stained in two cases. No correlation was evident between PD-L1 expression and survival in our series. Our results are indicative of near uniform absence of PD-L1 expression in MTC and its accompanying inflammatory cells; these results should be replicated on a larger scale in other centers. Definitive answers regarding the utility of PD1/PD-L1 immunophenotyping in MTC and of the use of checkpoint inhibitors in the treatment of this aggressive and rare thyroid cancer are expected from ongoing clinical trials, which should perform correlations with PD1/PD-L1 expression.
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Language: English
ISSN: 1479-6821
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Rights: OPEN
Accession Number: edsair.doi.dedup.....dd2c64599eee12ccde8e1fbd794a5705
Database: OpenAIRE