Table 3. Cox proportional hazard model for progression-free survival among the 272 advanced gastric cancer patients.

Parameters		Univariate analysis			Multivariate analysis
		HR	95% CI	P-value	HR	95% CI	P-value
Gender (ref: male)
	Female	1.036	0.712–1.507	0.855
Age (yr) (ref: <65)
	≥65	0.759	0.535–1.075	0.120
Pretreatment BMI (kg/m2) (ref: ≥18.5)
	<18.5	1.947	1.241–3.053	0.004	1.329	0.784–2.254	0.291
Tumor size (cm) (ref: <4)
	≥4	2.195	1.548–3.112	<0.001	1.449	0.988–2.126	0.058
Degree of differentiation (ref: well)
	Poorly	2.242	1.265–3.972	0.006	2.091	1.078–4.056	0.029
yp* T stage (ref: Tis and T0-2)
	T3-4	4.170	2.558–6.799	<0.001	2.309	1.266–4.211	0.006
yp* N stage (ref: N0)
	N1-3	5.524	3.321–9.186	<0.001	3.225	1.879–5.536	<0.001
yp* TNM stage (ref: T0N0M0, 0 and I)
	II-III	23.509	5.815–95.038	<0.001	NA	NA	NA
Post-operation chemotherapy (ref: present)
	Absent	1.687	0.983–2.895	0.058	1.749	0.951–3.217	0.072
Postoperative complications (ref: no)
	Yes	1.398	0.906–2.157	0.131
Severe complications (Clavien-Dindo ≥III) (ref: no)
	Yes	1.478	0.691–3.164	0.314
Pretreatment CONUT score (ref: ≤3)
	≥4	1.455	1.028–2.058	0.034	1.615	1.112–2.347	0.012
Pretreatment CEA (ng/mL) (ref: ≤5)
	>5	1.231	0.843–1.799	0.282

Considering that the yp T/yp N stages were significantly associated with the yp TNM stage, we didn't include the TNM stage in the final multivariate analysis.

Cox proportional multivariate hazards model was performed with the backward likelihood method.

HR = hazard ratio; CI = confidence interval; ref = reference; BMI = body mass index; Tis = tumor in situ; TNM = tumor-node-metastasis; CONUT = controlling nutritional status; CEA = carcinoembryonic antigen; NA = not applicable.

^*The yp prefix was used to indicate cases in which staging was performed following preoperative therapy.