Table 2.

C-indexes for the nomograms and TNM stage systems in patients with advanced ECCA

C-index	Training cohort		Validation cohort
	HR	95%CI	HR	95%CI
Overall survival	0.714	0.677–0.751	0.647	0.600–0.694
Cancer-specific survival	0.725	0.688–0.762	0.675	0.624–0.726
AJCC	0.651	0.612–0.690	0.591	0.548–0.634