Development and validation of survival nomograms for patients with differentiated thyroid cancer with distant metastases: a SEER Program-based study.

Abstract

We aimed to develop a nomogram model of overall survival (OS) and cancer-specific survival (CSS) in patients with differentiated thyroid cancer with distant metastases, and to evaluate and validate the nomogram. Also, its prognostic value was compared with that of the 8th edition of the American Joint Committee on Cancer tumor-node-metastasis staging system (AJCC8SS). Patients with distant metastatic differentiated thyroid cancer (DMDTC) from 2004 to 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) Program to extract the clinical variables used for analysis. A total of 906 patients were divided into a training set (n = 634) and validation set (n = 272). OS and CSS were selected as the primary end point and secondary end point. LASSO regression analysis and multivariate Cox regression analysis were applied to screen variables for constructing OS and CSS nomograms for survival probability at 3, 5, and 10years. Nomograms were evaluated and validated using the consistency index (C-index), time-dependent receiver operator characteristic (ROC) curves, area under the ROC curve, calibration curves, and decision curve analysis (DCA). The predictive survival of the nomogram was compared with that of AJCC8SS. Kaplan-Meier curves and log-rank tests were used to evaluate the risk-stratification ability OS and CSS nomograms. CS and CSS nomograms included six independent predictors: age, marital status, type of surgical procedure, lymphadenectomy, radiotherapy, and T stage. The C-index for the OS nomogram was 0.7474 (95% CI = 0.7199-0.775), and that for the CSS nomogram was 0.7572 (0.7281-0.7862). The nomogram showed good agreement with the "ideal" calibration curve in the training set and validation sets. DCA confirmed that the survival probability predicted by the nomogram had high clinical predictive value. The nomogram could stratify patients more accurately, and showed more robust accuracy and predictive power, than AJCC8SS. We established and validated prognostic nomograms for patients with DMDTC, which had significant clinical value compared with AJCC8SS.