Table 1.

Associations of PPFIA1 mRNA expression with clinicopathological variables of 179 ESCC patients from the GSE53625 dataset

Clinicopathological variables	Number	PPFIA1 expression		x2	P value
		Low	High
Gender				0.649	0.420
Male	146	125	21
Female	33	30	3
Age (years)				0.316	0.574
≤ 60	99	87	12
˃60	80	68	12
Smoking use				2.872	0.090
None	65	60	5
Yes	114	95	19
Alcohol use				0.637	0.425
None	73	65	8
Yes	106	90	16
Tumor location				0.771	0.680
Upper	20	16	4
Middle	97	85	12
Lower	62	54	8
Histological grade				1.557	0.459
I	32	29	3
II	98	86	12
III	49	40	9
Tumor invasion depth				7.935	0.019
T1-T2	39	38	1
T3	110	94	16
T4a	30	23	7
Lymph node metastasis				10.840	0.013
N0	83	76	7
N1	62	56	6
N2	22	15	7
N3	12	8	4
TNM stage				8.878	0.012
I	10	10	0
II	77	72	5
III	92	73	19
Adjuvant therapy				1.768	0.184
None	45	42	3
Yes	104	87	17
unknown	30

Abbreviations: PPFIA1 PTPRF interacting protein alpha 1, ESCC Esophageal squamous cell carcinoma, TNM tumor-node-metastasis