Table 1. Multivariable Cox regression analysis of prognosis for HCC patients.

Variables	Training cohort		Validation cohort		Total cohort
	HR (95% CI)	Pvalue	HR (95% CI)	Pvalue	HR (95% CI)	Pvalue
Overall survival
Age (>52 vs. ≤52)	1.34 (0.77 - 2.33)	0.305	1.13 (0.83 - 1.54)	0.443	1.13 (0.86 - 1.48)	0.368
Sex (male vs. female)	1.19 (0.36 - 3.99)	0.774	1.14 (0.71 - 1.85)	0.582	1.29 (0.83 - 1.99)	0.253
HBsAg (postive vs. negative)	1.69 (0.83 - 3.47)	0.149	1.14 (0.65 - 1.99)	0.657	1.19 (0.84 - 1.68)	0.339
TNM stage (III+IV vs. I+II)	3.01 (1.63 - 5.58)	<0.001	2.29 (1.55 - 3.37)	<0.001	1.74 (1.21 - 2.51)	0.003
Differentiation (Poor vs. Moderate+Well)	2.55 (1.47 - 4.93)	<0.001	2.11 (1.25 - 3.69)	<0.001	1.98 (1.17 - 3.08)	0.008
Serum AFP (≥200μg/L vs. <200μg/L)	2.42 (1.31 - 4.45)	0.005	1.81 (1.31 - 2.49)	<0.001	1.73 (1.31 - 2.28)	<0.001
mtDNA content (high vs. low)	1.89 (1.05 - 3.39)	0.034	1.88 (1.38 - 2.58)	<0.001	1.89 (1.44 - 2.48)	<0.001
Recurrence-free survial
Age (>52 vs. ≤52)	1.08 (0.66 - 1.78)	0.75	0.98 (0.77 - 1.25)	0.874	1.00 (0.81 - 1.24)	0.99
Sex (male vs. female)	1.12 (0.39 - 3.16)	0.836	1.26 (0.87 - 1.83)	0.225	1.31 (0.93 - 1.85)	0.125
HBsAg (postive vs. negative)	1.55 (0.82 - 2.96)	0.181	1.02 (0.67 - 1.54)	0.93	1.17 (0.75 - 1.81)	0.496
TNM stage (III+IV vs. I+II)	4.12 (2.36 - 7.20)	<0.001	1.83 (1.34 - 2.51)	<0.001	1.72 (1.28 - 2.32)	<0.001
Differentiation (Poor vs. Moderate+Well)	2.29 (1.38 - 3.85)	<0.001	2.06 (1.25 - 3.84)	<0.001	1.97 (1.17 - 2.93)	0.009
Serum AFP (≥200μg/L vs. <200μg/L)	1.84 (1.11 - 3.04)	0.018	1.61 (1.25 - 2.07)	<0.001	1.61 (1.29 - 2.02)	<0.001
mtDNA content (high vs. low)	1.90 (1.12 - 3.22)	0.018	1.84 (1.22 - 2.95)	<0.001	1.86 (1.29 - 2.98)	<0.001

Notes: mtDNA, mitochondrial DNA; HR: hazard ratio; 95% CI, 95% confidence interval. Significant P value was in bold. We calculated hazaed ratios and P values with an adjusted multivariate Cox proportional hazards regression model, including age, sex, HBsAg, TNM stage, differentiation, serum AFP and mtDNA content as covariates.