Molecular testing of mutations on thyroid nodules with indeterminate cytology: A prospective analysis of 112 patients in the north of Argentina.

TOLABA, NORMA; YAMILA SPEDALLETTI; PAOLA BAZZONI; MACARENA GALINDEZ; VALERIA CERIONI; CECILIA SANTILLAN; GILDA RICHTER; CECILIA HERRERA; LAURA SANCHEZ,; LEOPOLDO VAN CAWULAERT; MARTA A. TOSCANO,; MARCELO NALLAR; MARCELO MONTEROS ALVI,; CHRISTIAN MARTÍN MOYA

Endocrinologia Diabetes y Nutricion

Elsevier

Lugar: Barcelona; Año: 2022

2530-0164

Background: The detection of genetic mutations in thyroid nodules is an excellent instrument to improve the diagnosis and reduce the unnecessary surgeries of benign nodules. Here we analyzed the impact of a 7-gene mutation panel that includes point mutation in BRAF and RAS (H/N/K) and the gene fusions PAX8/PPARG, RET/PTC1 and RET/PTC2, in thyroid nodules from a population in North Argentina. Methods: We have performed a prospective analysis of 112 patients with fine needle aspirations with indeterminate cytology. According to the Bethesda classification, this includes samples characterized as Bethesda III, atypia of unknown significance/follicular lesion of unknown significance, and Bethesda IV, follicular neoplasm/suspicious for follicular neoplasm. The mutations of the 7-gene panel were associated to the postsurgical histology and ultrasound monitoring. Results: The presence of BRAF V600E and RET/PTC1 mutations were associatedwith malignant carcinoma in the 100% of cases (n: 8). However, only 37.5% (n: 3) of the nodules with RAS and 17% (n: 1) with PAX8/PPARG mutations were diagnosed as carcinoma. Based on histology and sonographic monitoring of nodules we estimate that this panel has an 86% of sensitivity in detecting malignant carcinoma, a 77% of specificity, a positive predictive value of 54% and a negative predictive value of 94%. The implementation of the molecular test reduced the number of surgeries by 48%. Conclusion: The 7-gene mutation panel allowed more individualized management patients bearing mutations, reduced the number of two-step surgeries, and promotedfollow up strategies in low-risk patients.