Development and validation of a prognostic nomogram for Hürthle cell thyroid carcinoma: a SEER-based study.

Background: Hürthle cell carcinoma is a rare subtype of thyroid cancer, and its clinical behavior and biological characteristics remain unclear. This study aimed to establish nomogram models for the prognostic evaluation of Hürthle cell thyroid carcinoma (HCTC) in terms of both cancer-specific survival (CSS) and overall survival (OS). Methods: Data for a total of 3,264 patients with HCTC (2004 to 2018) were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analysis was performed to identify significant predictors of prognosis and develop a prognostic nomogram. The performance of the model was assessed based on the area under the receiver operating characteristic curve (AUC), concordance index (c-index), and calibration curves. Results: Multivariate Cox regression analysis showed that age, sex, summary stage, tumor size, N stage, M stage, and treatment with thyroidectomy were independent predictors of OS. Moreover, age, summary stage, tumor size, N stage, M stage, AJCC stage, and treatment with thyroidectomy were significantly correlated with CSS. The c-index of the OS and CSS nomograms developed based on these factors was 0.822 (95% CI: 0.803-0.841) and 0.893 (95% CI: 0.866-0.920), respectively. The AUC was 0.888, 0.841, and 0.834 for 1-, 3-, and 5-year OS and 0.970, 0.949, and 0.933 for 1-, 3-, and 5-year CSS, respectively. The calibration curves showed good agreement between observed and predicted values. Moreover, decision curve analysis revealed that the nomogram had a better clinical utility than individual clinicopathological markers. Conclusions: A prognostic nomogram that allows the individualized assessment of OS and CSS in HCTC was developed. This nomogram could be used to guide treatment decisions in patients with HCTC.