Optimal extent of lymphadenectomy improves prognosis and guides adjuvant chemotherapy in esophageal cancer: A propensity score-matched analysis

Table 1 Clinicopathological information of the study population

Variables	Level	Overall
Number		1042
Sex, n (%)	Male	820 (78.7)
	Female	222 (21.3)
Age (yr), median (IQR)		60 (54, 66)
T, n (%)	1	98 (9.4)
	2	219 (21.0)
	3	487 (46.7)
	4	238 (22.8)
N, n (%)	0	612 (58.7)
	1	234 (22.5)
	2	134 (12.9)
	3	62 (6.0)
G, n (%)	Well differentiated	124 (11.9)
	Moderate differentiated	740 (71.0)
	Poor differentiated	178 (17.1)
Venous thrombus, n (%)	Negative	887 (85.1)
	Positive	155 (14.9)
Perineurial invasion, n (%)	Negative	509 (75.0)
	Positive	170 (25.0)
NPLN, mean (SD)		1.17 (2.15)
RPLN, mean (SD)		0.06 (0.11)
NRLN, mean (SD)		19.67 (9.81)
Adjuvant chemotherapy, n (%)	No	599 (57.5)
	Yes	443 (42.5)

IQR: Interquartile range; NPLN: Number of positive lymph nodes; RPLN: Ratio of positive lymph nodes.

Table 2 Univariate analysis for overall survival

Prognostic factors		P value	HR (95%CI)
Age		0.576	1 (0.99-1.01)
Maximal tumor diameter		0.038	1.01 (1-1.01)
NRLN		0.049	0.83 (0.68-1)
Sex (ref male)		0.634	0.95 (0.76-1.18)
Tumor location (ref upper)
	Middle	0.065	0.71 (0.49-1.02)
	Lower	0.051	0.65 (0.43-1)
T (ref T1)
	T2	0.028	1.78 (1.07-2.99)
	T3	< 0.001	2.8 (1.74-4.52)
	T4	< 0.001	2.71 (1.65-4.44)
N (ref N0)
	N1	< 0.001	2.04 (1.64-2.53)
	N2	< 0.001	2.35 (1.82-3.02)
	M3	< 0.001	3.38 (2.45-4.65)
G (ref G1)
	G2	0.006	1.57 (1.14-2.15)
	G3	0.002	1.81 (1.25-2.61)
Venous thrombus (ref negative)	Positive	< 0.001	2.1 (1.68-2.63)
Perineurial Invasion (ref negative)	Positive	< 0.001	1.79 (1.41-2.29)
Adjuvant chemotherapy (ref no)	Yes	0.009	1.27 (1.06-1.52)

NRLN: Number of removed lymph nodes; HR: Hazards regression; CI: Confidence interval.

Table 3 Multivariate analysis for overall survival

Prognostic factors		P value	HR (95%CI)
Maximal tumor diameter		0.667	1 (0.99-1.01)
T (ref T1)
	T2	0.055	2.04 (0.99-4.20)
	T3	0.002	3.09 (1.51-6.31)
	T4	0.005	7.44 (1.82-30.35)
N (ref N0)
	N1	0.077	1.35 (0.97-1.89)
	N2	0.075	1.46 (0.96-2.21)
	M3	0.002	1.99 (1.28-3.11)
G (ref G1)
	G2	0.103	1.42 (0.93-2.16)
	G3	0.387	1.25 (0.76-2.05)
Venous thrombus (ref negative)	Positive	< 0.001	1.8 (1.34-2.42)
Perineurial invasion (ref negative)	Positive	0.088	1.29 (0.96-1.71)
Adjuvant chemotherapy (ref no)	Yes	0.738	0.95 (0.71-1.27)
NRLN (ref ≤ 21)	> 21	0.004	0.66 (0.50-0.87)

NRLN: Number of removed lymph nodes; HR: Hazards regression; CI: Confidence interval.