Development and validation of novel nomograms to predict survival of patients with tongue squamous cell carcinoma

Abstract

Background: There is no unified standard to predict postoperative survival in patients with tongue squamous cell carcinoma (TSCC), hence the urgency to develop a model to accurately predict the prognosis of these patients.

Aim: To develop and validate nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) of patients with TSCC.

Methods: A cohort of 3454 patients with TSCC from the Surveillance, Epidemiology, and End Results (SEER) database was used to develop nomograms; another independent cohort of 203 patients with TSCC from the Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhejiang University School of Medicine, was used for external validation. Univariate and multivariate analyses were performed to identify useful variables for the development of nomograms. The calibration curve, area under the receiver operating characteristic curve (AUC) analysis, concordance index (C-index), net reclassification index (NRI), and decision curve analysis (DCA) were used to assess the calibration, discrimination ability, and clinical utility of the nomograms.

Results: Eight variables were selected and used to develop nomograms for patients with TSCC. The C-index (0.741 and 0.757 for OS and CSS in the training cohort and 0.800 and 0.830 in the validation cohort, respectively) and AUC indicated that the discrimination abilities of these nomograms were acceptable. The calibration curves of OS and CSS indicated that the predicted and actual values were consistent in both the training and validation cohorts. The NRI values (training cohort: 0.493 and 0.482 for 3- and 5-year OS and 0.424 and 0.402 for 3- and 5-year CSS; validation cohort: 0.635 and 0.750 for 3- and 5-year OS and 0.354 and 0.608 for 3- and 5-year CSS, respectively) and DCA results indicated that the nomograms were significantly better than the tumor-node-metastasis staging system in predicting the prognosis of patients with TSCC.

Conclusion: Our nomograms can accurately predict patient prognoses and assist clinicians in improving decision-making concerning patients with TSCC in clinical practice.

Keywords: Cancer-specific survival; Nomogram; Overall survival; Prognosis; Tongue squamous cell carcinoma.

Figure 1

Flowchart of data selection. SEER: Surveillance, Epidemiology, and End Results; TSCC: Tongue squamous cell carcinoma.

Figure 2

Nomograms predicting the 3- and 5-year overall survival and cancer-specific survival in patients with squamous cell carcinoma of the tongue. A: Nomogram predicting the 3- and 5-year overall survival (OS) in patients with squamous cell carcinoma of the tongue (TSCC); B: Nomogram predicting the 3- and 5-year cancer-specific survival (CSS) in patients with TSCC. The points for each variable were summed, and the probabilities of 3- and 5-year OS and CSS were predicted based on the total number of points (shown at the bottom of the nomogram). For example, consider a 60-year-old unmarried patient with moderately differentiated T2 and N1 stage cancer on the anterior 2/3 of tongue who underwent neck dissection and postoperative chemotherapy. Top red lines represent the points for each variable, the sum (209) of these points is the total score, and the bottom red line indicates the probabilities of 3- (64%) and 5-year (55%) overall survival.

Figure 3

Calibration curves for 3- and 5-year overall survival and 3- and 5-year cancer-specific survival in patients with squamous cell carcinoma of the tongue. A: Calibration curves for 3-year overall survival (OS) in the training cohort; B: Calibration curves for 5-year OS in the training cohort; C: Calibration curves for 3-year OS in the validation cohort; D: Calibration curves for 5-year OS in the validation cohort; E: Calibration curves for 3-year cancer-specific survival (CSS) in the training cohort; F: Calibration curves for 5-year CSS in the training cohort; G: Calibration curves for 3-year CSS in the validation cohort; H: Calibration curves for 5-year CSS in the validation cohort. The gray line indicates perfect prediction. Blue lines indicate 95% confidence intervals (CIs). The red line indicates nomogram performance. Red and gray lines close together indicates greater nomogram accuracy.

Figure 4

Receiver operating characteristic curves of the nomograms and tumor-node-metastasis staging system for overall survival and cancer-specific survival in patients with squamous cell carcinoma of the tongue. A: Receiver operating characteristic curves (ROC) for 3-year overall survival (OS) in the training cohort; B: ROC for 5-year OS in the training cohort; C: ROC for 3-year OS in the validation cohort; D: ROC for 5-year OS in the validation cohort; E: ROC for 3-year cancer-specific survival (CSS) in the training cohort; F: ROC for 5-year CSS in the training cohort; G: ROC for 3-year CSS in the validation cohort; H: ROC for 5-year CSS in the validation cohort. TNM: Tumor-node-metastasis.

Figure 5

Decision curve analysis of the accuracy of the nomograms and tumor-node-metastasis staging system for predicting overall survival and cancer-specific survival in patients with squamous cell carcinoma of the tongue. A: 3-year overall survival (OS) benefits in the training cohort; B: 5-year OS benefits in the training cohort; C: 3-year OS benefits in the validation cohort; D: 5-year OS benefits in the validation cohort; E: 3-year cancer-specific survival (CSS) benefits in the training cohort; F: 5-year CSS benefits in the training cohort; G: 3-year CSS benefits in the validation cohort; H: 5-year CSS benefits in the validation cohort. TNM: Tumor-node-metastasis.