Thoracic para-aortic lymph node recurrence in patients with esophageal squamous cell carcinoma: A propensity score-matching analysis

Table 1 Main characteristics

	TPLN (+)	Before matching		After matching
		TPLN (-)	P value (df)	TPLN (-)	P value (df)
Age, median, yr	56.5	59	0.19	57.5	0.76
Sex			1.00 (1)		1.00 (1)
Male	14	156		78
Female	4	45		20
Location			0.73 (2)		0.87 (2)
Upper	0	6		1
Middle	10	115		50
Lower	8	80		47
Grade			0.31 (3)		0.50 (3)
I	0	21		5
II	11	133		68
III	6	39		23
Unknown	1	8		2
T stage			0.85 (3)		0.82 (3)
T1	0	5		1
T2	3	33		11
T3	14	157		83
T4	1	6		1
N stage			0.43 (3)		0.76 (3)
N0	4	75		25
N1	6	61		28
N2	7	48		32
N3	1	17		13
Adjuvant therapy			0.70 (2)		0.91 (2)
Chemoradiotherapy	3	24		14
Chemotherapy	8	109		49
None	7	68		35

df: Degree of freedom; TPLN: Thoracic paraaortic lymph node.