TABLE 4.

C‐statistics for the prediction of disease recurrence

	C‐statistics for model with disease recurrence
Model	C‐index	Difference (95% CI)	Model comparison p‐value
Model 1: Surgery	0.516	NA	NA
Model 2: Surgery + tumor size	0.718	0.202 (−0.015, 0.419)	0.041
Model 3: Surgery + tumor volume	0.565	0.049 (−0.018, 0.117)	0.754
Model 4: Surgery + solid size	0.523	0.007 (−0.075, 0.089)	0.871
Model 5: Surgery + stage	0.740	0.224 (−0.079, 0.527)	0.032

Note: Model comparison between Model 1 vs. Model 2, Model 1 vs. Model 3, Model 1 vs. Model 4 and Model 1 vs. Model 5.