Table 2.

C-indices for the nomogram and TNM system in the two groups

Characteristics	Training cohort			Validation cohort
	C-index	95% CI	P value	C-index	95% CI	P value
nRT group
Nomogram	0.652	0.614-0.690		0.663	0.606-0.720
TNM 7th stage	0.595	0.556-0.634	0.003*	0.597	0.541-0.654	0.016*
TNM 8th stage	0.580	0.543-0.617	<0.001*	0.588	0.534-0.641	0.007*
non-nRT group
Nomogram	0.754	0.723-0.785		0.747	0.688-0.800
TNM 7th stage	0.717	0.685-0.749	0.027	0.681	0.625-0.736	0.016

^*compared with nomogram.