Detection of RAS mutation by pyrosequencing in thyroid cytology samples

作者：Guerra Anna; Carrano Mario; Angrisani Elisabetta; Puzziello Alessandro; Izzo Giulia; Di Crescenzo Vincenzo; Vatrella Alessandro; Vitale Mario^*

来源：International Journal of Surgery, 2014, 12: S91-S94.

DOI：10.1016/j.ijsu.2014.05.045

• Thyroid carcinoma
• RAS
• FNAC

Introduction: Fine-needle aspiration cytology (FNAC) is the primary means to distinguish benign from malignant thyroid nodules. However, adjunctive diagnostic tests are needed as 20-40% of FNAC are inconclusive. RAS mutations have been described in differentiated thyroid cancer and they could be used as tumor markers. However, their prevalence varies widely among studies, probably as a result of the detection methods used. We investigated whether the pyrosequencing method can be applied to detect NRAS and KRAS mutations in thyroid aspirates. %26lt;br%26gt;Patients and methods: A total of 37 thyroid aspirates, including benign hyperplastic nodules (HBN, N = 16) and follicular thyroid carcinomas (FTC, N = 21) were analyzed for the presence of NRAS(61) and KRAS13 mutations. %26lt;br%26gt;Results: A RAS mutation was found in 31% and 62% of BN and FTC respectively. Most samples displayed a percentage of mutated alleles lower than 50% (median -30.8% and 15.3% in FTC and HBN respectively), a result compatible with the presence of extra-nodular cells contaminating the FNA or with the subclonal nature of both types of thyroid nodules. %26lt;br%26gt;Discussion: Pyrosequencing is a reliable assay to detect RAS mutations in fine-needle thyroid aspirates. %26lt;br%26gt;Conclusions: The low specificity and sensitivity limit the power of this test to distinguish between FTC and benign nodules in inconclusive FNACs.

• 出版日期2014-8