Purpose: The prognostic importance of RET and RAS mutations and their relationship to clinicopathologic parameters and outcomes in medullary thyroid carcinoma (MTC) needs to be clarified. Experimental design: A multicenter retrospective cohort study was performed utilizing data from 290 patients with MTC. The molecular profile was determined and associations were examined with clinicopathologic data and outcomes. Results: RET germline mutations were detected in 40 patients (16.3%). Somatic RET and RAS mutations occurred in 135 (46.9%) and 57 (19.8%) patients respectively. RETM918T was the most common somatic RET mutation (n=75). RET somatic mutations were associated with male sex, larger tumor size, advanced AJCC stage, vascular invasion (VI), and high IMTCGS grade. When compared with other RET somatic mutations, RETM918T was associated with younger age, AJCC (8th edition) IV, vascular invasion, extrathyroidal extension, and positive margins. RET somatic or germline mutations were significantly associated with reduced distant metastasis free survival on univariate analysis but there were no significant independent associations on multivariable analysis, after adjusting for tumor grade and stage. There were no significant differences in outcomes between RET somatic and RET germline mutations, or between RETM918T and other RET mutations. Other recurrent molecular alterations included TP53 (4.2%), ARID2 (2.9%), SETD2 (2.9%), KMT2A (2.9%), and KMT2C (2.9%). Among them, TP53 mutations were associated with decreased overall and disease-specific survival, independently of tumor grade and AJCC stage. Conclusions: RET somatic mutations were associated with high-grade, aggressive primary tumor characteristics, and decreased distant metastatic-free survival but this relationship was not significant after accounting for tumor grade and disease stage . RETM918T was associated with aggressive primary tumors but was not independently associated with clinical outcomes. TP53 mutation may represent an adverse molecular event associated with decreased overall and disease-specific survival in MTC but its prognostic value needs to be confirmed in future studies.

Purpose: RAS mutations occur across the spectrum of thyroid neoplasms, and more tools are needed for better prognostication. The objective of this study was to evaluate how additional genetic events affecting key genes modify prognosis in patients with RAS-mutant thyroid cancers, and specifically differentiated thyroid cancers (DTC). Experimental Design: We performed a clinical–genomic analysis of consecutive patients with DTC, poorly differentiated (PDTC), or anaplastic thyroid cancer (ATC) between January 2014 and December 2021, in whom a custom-targeted next-generation sequencing assay was performed. Patients harboring RAS mutations were included, and we compared their clinical features and outcomes based upon the presence of additional oncogenic alterations. Results: Seventy-eight patients were identified, with 22% (17/78) harboring a driver RAS mutation plus an additional oncogenic alteration. All six (100%) ATCs had an additional mutation. Compared with DTCs harboring a solitary RAS mutation, patients with DTC with RAS and additional mutation(s) were more likely to be classified as American Thyroid Association high-risk of recurrence (77% vs. 12%; P < 0.001) and to have larger primary tumors (4.7 vs. 2.5 cm; P = 0.002) and advanced stage (III or IV) at presentation (67% vs. 3%; P < 0.001). Importantly, over an average 65-month follow-up, DTC-specific-mortality was more than 10-fold higher (20% vs. 1.8%; P = 0.011) when additional mutations were identified. Conclusions: Identification of key additional mutations in patients with RAS-mutant thyroid cancers confers a more aggressive phenotype, increases mortality risk in DTC, and can explain the diversity of RAS-mutated thyroid neoplasia. These data support genomic profiling of DTCs to inform prognosis and clinical decision-making.

The introduction and generalization of next-generation sequencing techniques have significantly increased the identification of mutations in thyroid tumors from multiple patient cohorts. The understanding of the association between specific mutations and clinical outcomes is gradually leading to individualizing the care of patients with thyroid cancer. BRAF^V600 is the most common mutation seen in thyroid cancer patients and unequivocally predicts malignancy, but when considered in isolation, it is not recommended to be used as an independent prognostic factor. Mutations in RAS are the second most common alterations in thyroid cancer but can be found in benign and malignant lesions. Rearrangements involving receptor tyrosine kinases, primarily RET, are found in a subset of thyroid tumors without mutations in either BRAF or RAS. The assessment of additional mutations is increasingly employed in thyroid cancer prognostication. The coexistence of BRAF with alterations in genes such as PIK3CA, TERT promoter, or TP53 is associated with less favorable outcomes. Similar studies have also shown that additional oncogenic mutations in RAS-mutant thyroid carcinoma, such as those affecting the EIF1AX gene, likely predict a more aggressive clinicopathologic behavior. Overall, emerging evidence suggests that the co-occurrence of specific alterations in defined genes with BRAF or RAS mutations can become prognostic tools and useful predictors of thyroid tumor aggressiveness.

Background: Large scale epidemiology studies have suggested obesity may increase the risk of thyroid cancer, though no prospective analyses using real-world measurement of BMI at a time proximate to initial thyroid nodule evaluation have been performed.Methods: We performed a prospective, cohort analysis over 3 years of consecutive patients presenting for thyroid nodule evaluation. We measured BMI proximate to the time of initial evaluation and correlated this with the final diagnosis of benign or malignant disease. We further correlated patient BMI with aggressivity of thyroid cancer, if detected.Results: Among 1,259 consecutive patients with clinically relevant nodules, 199(15%) were malignant. BMI averaged 28.6 kg/m² (SD: 6.35, range:16.46-59.26). There was no correlation between the measurement of BMI and risk of thyroid cancer (p=0.58) as mean BMI was 28.9 kg/m² and 28.6 kg/m² in cancerous and benign cohorts, respectively. Similarly, BMI did not predict aggressive thyroid cancer (p=0.15). While overall nodule size was associated with increased BMI (p<0.01), these data require further validation as obesity may hinder nodule detection until large.Conclusion: In contrast to findings published from large scale association studies drawn from national databases, these prospective data of consecutive patients presenting for nodule evaluation detect no association of obesity (as measured by BMI) with thyroid cancer. Real time measurement of BMI at the time of thyroid nodule evaluation does not contribute to cancer risk assessment.

Context: Oncocytic cells can occur in benign and malignant thyroid nodules, posing a diagnostic challenge. This has reduced the diagnostic performance of molecular testing for indeterminate oncocytic thyroid nodules. Objective: To evaluate the performance of Afirma genomic sequencing classifier (GSC) in thyroid nodules with Bethesda III or IV cytology and oncocytic predominance. Design, setting, patients, and intervention: A multicenter retrospective study was conducted in adults with Bethesda III and IV thyroid nodules showing oncocytic predominance who underwent a fine-needle aspiration biopsy and Afirma GSC testing between July 2017 and December 2023. Variables included presence of Hashimoto's thyroiditis and Thyroid Imaging Reporting and Data System (TIRADS) classification. Main outcome measures: Outcomes included benign call rate (BCR), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of Afirma GSC testing. Results: Of 359 nodules (57% Bethesda III, 43% Bethesda IV) tested with Afirma GSC, the mean nodule size was 2.0 cm. BCR was 81% and 74% for Bethesda III and IV nodules, respectively. GSC sensitivity, specificity, PPV, and NPV were 89%, 86%, 24%, and 99% for Bethesda III nodules and 94%, 87%, 50%, and 99% for Bethesda IV nodules, respectively. A concurrent diagnosis of Hashimoto's thyroiditis significantly reduced the specificity and PPV in Bethesda III nodules. TIRADS classification did not affect the BCR or PPV in Bethesda III or IV nodules. Conclusion: Afirma GSC has a high BCR and improved performance over earlier generation molecular tests in oncocytic thyroid nodules, particularly for Bethesda IV. However, the PPV in Bethesda III nodules remains low, especially in the presence of Hashimoto's thyroiditis.