Construction and validation of novel nomograms based on the log odds of positive lymph nodes to predict the prognosis of papillary thyroid cancer: a retrospective cohort study

Abstract

Objective: This study aims to assess the long-term prognostic significance of the log odds of positive lymph nodes (LODDS) in patients diagnosed with papillary thyroid cancer (PTC) and to develop a novel nomogram for predicting long-term overall survival (OS).

Methods: The cohort was randomly divided at a ratio of 7:3 from the Surveillance, Epidemiology, and End Results (SEER) database. Additionally, patient data from a medical center in China served as an external validation cohort. Nomograms were constructed using data from the training cohort and subsequently validated using both internal and external validation cohorts to predict 120- and 180-month OS in PTC patients. The predictive performance and clinical utility of the nomogram were assessed using various metrics, including the concordance index (C-index), time-dependent receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), Integrated Discriminant Improvement Index (IDI), and Net Reclassification Improvement Index (NRI).

Results: LODDS is an independent prognostic factor for PTC, a nomogram demonstrating high accuracy in predicting long-term OS. The C-index values, and time-dependent area under the curve (AUC) indicated well discriminatory ability of the nomogram. Calibration plots exhibited high concordance, while DCA, NRI, and IDI analyses revealed superior performance of the nomogram compared to AJCC staging system.

Conclusion: The clinical prediction model incorporating LODDS exhibits robust predictive performance, aiding in the assessment of long-term prognosis post-surgery in PTC patients. It serves as a valuable adjunct to the AJCC system, offering a scientific basis for guiding interventions and rehabilitation strategies for PTC patients following surgery.

Keywords: SEER; long-term overall survival; nomogram; papillary thyroid cancer; post-operative.

Figure 1

Flow chart for PTC patients. PTC, papillary thyroid cancer; SEER, the Surveillance, Epidemiology, and End Results; Sub, submission; ICD-O-3, International Classification of Diseases for Oncology, 3rd Edition.

Figure 2

Nomogram predicting 120-month and 180-month OS of patients with PTC. OS, overall survival; PTC, papillary thyroid cancer; LODDS, log odds of positive lymph nodes.

Figure 3

Comparison of the ROC curves (A, B), calibration plots (C, D), and decision curve analysis curves (E, F) of the two candidate models (AJCC stage and Nomogram) for 120- and 180-month OS prediction in the training cohort. ROC, receiver operating characteristic; OS, overall survival; AJCC, American Joint Committee on Cancer.

Figure 4

Comparison of the ROC curves (A, B), calibration plots (C, D), and decision curve analysis curves (E, F) of the two candidate models (AJCC stage and Nomogram) for 120- and 180-month OS prediction in the internal validation cohort. ROC, receiver operating characteristic; OS, overall survival; AJCC, American Joint Committee on Cancer.

Figure 5

Comparison of the ROC curves (A, B), calibration plots (C, D), and decision curve analysis curves (E, F) of the two candidate models (AJCC stage and Nomogram) for 120- and 180-month OS prediction in the external validation cohort. ROC, receiver operating characteristic; OS, overall survival; AJCC, American Joint Committee on Cancer.

Figure 6

Nomogram clinical applications of nomogram predicting 120-month and 180-month OS of PTC patients. OS, overall survival; PTC, papillary thyroid cancer; LODDS, log odds of positive lymph nodes.