Table 2.

Analysis of factors associated with PFS and OS.

Factor	PFS				OS
	Univariate		Multivariate		Univariate		Multivariate
	HR (95% CI)	p Value	HR (95% CI)	p Value	HR (95% CI)	p Value	HR (95% CI)	p Value
Age >65 years	1.09 (0.56–2.10)	0.8			0.98 (0.47–2.04)	0.964
Stage (III versus IV)	1.57 (0.72–3.44)	0.258			2.85 (0.99–8.19)	0.052	3.21 (1.05–9.78)	0.04
Tumor size: >3.7 cm	0.83 (0.43–1.59)	0.572			2.15 (2.03–4.49)	0.041	4.2 (1.73–10.31)	0.002
N stage	1.88 (1.06–3.32)	0.03	1.69 (0.94–3.02)	0.079	3.07 (1.52–6.18)	0.002	3.44 (1.59–7.42)	0.002
cfDNA average: >9.71 ng/mL	6.85 (3.28–14.27)	<0.001	6.25 (3–13.02)	<0.001	4.16 (2.01–8.63)	<0.001	6.75 (2.85–16)	<0.001
CA19-9: >34 U/mL	1.70 (0.6–4.82)	0.317			1.97 (0.60–6.51)	0.267

CA19-9, carbohydrate antigen 19-9; cfDNA, cell-free DNA; HR, hazard ratio; OS, overall survival; PFS, progression-free survival.