Clinical detection of “extremely low‐risk” follicular thyroid carcinoma: A population‐based study of 7304 patients

BACKGROUND: Previous studies have not been consistent in the risk of metastasis in follicular thyroid carcinoma (FTC). Therefore, we conducted a large population study to stratify the risk of distant metastasis in FTC patients using only clinical parameters. METHODS: We extracted FTC patients from The Surveillance, Epidemiology, and End Results (SEER) database and divided them into training and validation cohorts. RESULTS: The two cohorts consisted of 4913 and 2391 patients, respectively. We developed a nomogram and risk table based on a logistic regression model using algorithm‐selected variables. Receiver Operating Characteristic (ROC) analyses showed high discriminatory power in the training and validation cohorts (Area under the curve [AUC] of 0.85 and 0.84, respectively). Extremely low, low, intermediate, and high‐risk groups had 0.3%, 1%, 3.5%, and 16.7% risk of distant metastasis, respectively. CONCLUSIONS: Our risk scoring table can separates patients into four risk groups and efficiently detect patients with almost no risk of metastasis.