Molecular profiling of follicular variant of papillary thyroid cancer reveals low-risk noninvasive follicular thyroid neoplasm with papillary-like nuclear features: A paradigm shift to reduce aggressive treatment of indolent tumors
| Autor: | Nelson George, Amit Agarwal, Niraj Kumari, Sarita Agarwal, Narendra Krisnani, Sushil Kumar Gupta |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
BRAF mutations
infiltrative/diffusing follicular variant of papillary thyroid cancer invasive encapsulated follicular variant of papillary thyroid carcinoma iodine-metabolizing genes noninvasive follicular thyroid neoplasm with papillary-like nuclear features RAS mutations Diseases of the endocrine glands. Clinical endocrinology RC648-665 Diseases of the digestive system. Gastroenterology RC799-869 |
| Zdroj: | Indian Journal of Endocrinology and Metabolism, Vol 22, Iss 3, Pp 339-346 (2018) |
| Druh dokumentu: | article |
| ISSN: | 2230-8210 |
| DOI: | 10.4103/ijem.IJEM_86_18 |
| Popis: | Introduction: Encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) has been reclassified into noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and invasive EFVPTC. NIFTP is considered a low-risk neoplasm. Therefore, follicular variant of papillary thyroid cancer (FVPTC) presently has two distinct histopathological subtypes – invasive EFVPTC and infiltrative/diffuse FVPTC. Molecular characteristics of these groups remain unclear. Methodology: Thirty FVPTCs (10 NIFTPs, 12 invasive EFVPTCs, and 8 infiltrative/diffuse variants) were reviewed and screened for BRAF and RAS mutations by restriction fragment length morphism-polymerase chain reaction (PCR) and Sanger sequencing. The mRNA expression levels of iodine-metabolizing genes were analyzed using real-time PCR. The mutations status and mRNA expression levels were correlated with clinicopathological features. Results: All 10 NIFTPs had predominant follicular pattern. One case showed NRAS mutation, whereas none showed BRAF mutation. All invasive EFVPTC had capsular and/or lymphovascular invasion and 4/12 showed lymph node metastasis. BRAF and NRAS were seen in three cases each of invasive FVPTC. All eight infiltrating/diffuse FVPTCs showed infiltration into adjacent thyroid parenchyma and lymph node metastasis. Conclusion: BRAF mutation was observed in 62.5% of cases; however, no NRAS mutation was found. Sodium iodide symporter (NIS) expressions in NIFTP were similar to that of normal thyroid tissue, whereas it was downregulated in invasive and infiltrative/diffuse FVPTC. Our study supports the argument that NIFTP can be considered as low-risk follicular thyroid neoplasm. Those tumors that harbor BRAF mutations may be offered a complete thyroidectomy because they show decreased expression of NIS gene which confers a tendency to lose radioactive iodine avidity and further recurrence of the tumor. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|