RE: A Risk Prediction Model of Thyroid Cancer in Euthyroid Asymptomatic Patients: Importance of Model Validation

Dear Sir, With great interest, we read the article “risk of thyroid cancer in euthyroid asymptomatic patients with thyroid nodules, with an emphasis on family history of thyroid cancer” by Hwang et al. (1). The paper concludes that a solitary lesion on ultrasonography (US) features observed on US, and the male gender (p < 0.001) were significant independent risk factors for thyroid malignancy (1). We would like to thank the authors for this highly useful work. The authors developed a multivariate regression prediction model to investigate the independent predictive factors associated with thyroid cancer in euthyroid asymptomatic patients. Model predictors include age, male gender, 1st degree family history, solitary lesion on US, serum TSH level, and TSH grade. Multivariate analysis confirmed that a solitary lesion on US (odds ratio [OR], 1.413; 95%