A meta-analysis-derived proposal for a clinical, ultrasonographic, and cytological scoring system to evaluate thyroid nodules: the "CUT" score

The purpose of this study is to develop a new cancer risk score for preoperative assessment of thyroid nodules (TN) trying to reduce unnecessary thyroidectomies. On the basis of a recent meta-analysis of published literature, we assigned a matching value to the clinical (C) and ultrasonographic (U) features of TN with increased malignancy risk (MR). The created "CUT" score derived from "C+U" score, (CU[1-10] ), along with the five-tiered "T" (T[1-5] ), represents the cytologic result of the fine-needle aspiration. The C+U score was prospectively applied to 683 consecutive patients with 705 TN and validated through a ROC curve analysis. The CUT score was correlated with the histopathological diagnoses of 110 surgically resected TN. Fifty-five histologically benign TN had a mean C+U score of 2.4 versus 5.7 of 55 malignant TN (p < 0.001). Three categories were identified: low risk for C+U score ≤2.5 (MR: 9 %), intermediate risk for C+U score ≥2.75 and ≤5 (MR: 38 %), and high risk for C+U score ≥5.25 (MR: 95 %). Sensitivity and specificity were, respectively, 95 and 60 % for a cut-off value >2.5, and 69 and 96 % for >5. The "CUT" score can be easily applied, aiding clinicians in the evaluation of TN, especially in cases with indeterminate or repeated non-diagnostic FNA.