Table 3. AIC and C-index for four models.

Model	AIC	C-index	Concordance
LASSO	33,431	0.710	0.710 (0.703–0.717)
COX	33,420	0.712	0.712 (0.705–0.719)
TNM	34,043	0.637	0.637 (0.631–0.644)
TTNNMM	33,994	0.651	0.651 (0.644–0.657)

LASSO model: the model fit by Cox regression after variables selection by LASSO Cox regression; COX model: the model fit by Cox regression; TNM model: the model established in first time T, N, M grade; TTNNMM model: the model established in first and second times T, N, M grade. AIC, akaike information criterion; LASSO, least absolute shrinkage and selection operator.