2017;6(5):1014C1022. analyzed separately (HT vs non-HT: 24.5% vs 16.3% solitary; 22.1% vs 15.4% multinodular; 0.01). Conclusion HT increases the risk of thyroid malignancy in any patient presenting for nodule evaluation. Diffuse sonographic heterogeneity and/or TPOAb positivity should be used for risk assessment at time of evaluation. or Mann-Whitney tests for continuous variables, according to the data distribution as evaluated by Kolmogorov-Smirnov test. For analysis, we calculated the relative risks (RRs), the 95% CIs, and the pooled effects. A two-sided value 0.05 was considered significant. All calculations were performed using SPSS, version 25 (IBM, Armonk, NY). Permission for this study was granted by the Brigham and Womens Hospital institutional review board. 2. Results Our final study population included 9851 patients with 21,397 relevant nodules. Pdgfra As expected, the population was predominantly female (83.9%) and had a mean age of 52.2 years. Within the evaluable cohort, 14,063 (66%) nodules were aspirated. The remaining nonaspirated nodules were generally cystic, small, had sonographically benign characteristics, or were resected in conjunction with a separate WR 1065 index nodule prompting concern in the same gland. Baseline patient and nodules characteristics are summarized in Table 1. Table 1. Baseline Patient and Nodule Characteristics 0.01). An WR 1065 increase in malignant cytology was similarly identified in patients with HT (RR, 1.7; 95% CI, 1.44 to 1 1.99; 0.01; Fig. 1). Table 2. Influence of HT on Nodule Cytology Classification According to TBSRTC Valuevalue for 2 6 0.01; Fig. 2). This increased cancer prevalence was maintained when patients with solitary or multiple nodules were analyzed separately, suggesting a field effect of HT itself (HT vs non-HT groups: 24.5% vs 16.3% in solitary nodules; 22.1% vs 15.4% in multinodular glands; WR 1065 0.01). The types and proportions of thyroid cancer in both groups are listed in Table 3. The frequency of malignancy was also higher in the setting of HT when we evaluated only patients with a final indeterminate cytology (HT vs non-HT: 43.1% vs 38.7%; 0.05). The association between HT and thyroid cancer according to the final cytological WR 1065 diagnosis is reported in Table 4. Open in a separate window Figure 2. Relative risk of having one or more malignant nodules vs no malignant nodules given HT. Table 3. Association Between HT and Thyroid Cancer ValueValueValueJ.H.L. has received research support from Bristol-Myers Squibb, Bayer; and Novartis; and consulting fees from Bayer, Genentech, and Eisai. The remaining authors have nothing to disclose. Glossary Abbreviations:FNAfine-needle aspirationHTHashimoto thyroiditisRRrelative riskTBSRTCThe Bethesda System for Reporting Thyroid CytopathologyTPOAbthyroid peroxidase antibody References and Notes 1. Vanderpump MP. The epidemiology of thyroid disease. Br Med Bull. 2011;99(1):39C51. [PubMed] [Google Scholar] 2. Delemer B, Aubert JP, Nys P, Landron F, Boue S. An observational study of the initial management of hypothyroidism in France: the ORCHIDE study. Eur J Endocrinol. 2012;167(6):817C823. [PMC free article] [PubMed] [Google Scholar] 3. McLeod DS, Cooper DS. The incidence and prevalence of thyroid autoimmunity. Endocrine. 2012;42(2):252C265. [PubMed] [Google Scholar] 4. Vanderpump MP, Tunbridge WM, French JM, Appleton D, Bates D, Clark F, Grimley Evans J, Hasan DM, Rodgers H, Tunbridge F, Young ET..