Exploring the role of chitinase-3-like protein 1 in recurrence patterns among patients with differentiated thyroid cancer.

Our understanding of the oncogenic drivers involved in thyroid cancers continues to expand. In a recent issue of this journal, Cheng et al explore the role of chitinase-3-like protein 1 (CHI3L1) in the development of thyroid cancer and its recurrence. They show increased levels of CHI3L1 in papillary and anaplastic thyroid malignancies (PTC and ATC, respectively) but baseline expression of the protein in benign thyroid pathologies. These were most pronounced in PTCs with BRAF mutations. High levels of CHI3L1 were shown to be associated with a higher likelihood of extrathyroidal extension and lymph node metastasis, more advanced TNM stage, a higher frequency of harboring a BRAF mutation, and a higher risk of disease recurrence. Pathologic features, including clonogenicity, migratory, invasive and angiogenic properties, were reduced in a CHI3L1-knockdown thyroid cancer cell line. The cysteine-rich angiogenic inducer 61 (CYR61) pathway was identified as a potential mediator of CHI3L1 pathogenesis, but a full mechanistic pathway was not delineated. Findings regarding CHI3L1-associated pathogenicity are in line with published data available for a number of other cancers. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.