Single nucleotide polymorphism rs13042395 in the SLC52A3 gene as a biomarker for regional lymph node metastasis and relapse-free survival of esophageal squamous cell carcinoma patients

Table 1 Characteristics of ESCC cases and controls

Variables	SNP and ESCC risk		SNP and ESCC progression	SNP and ESCC prognosis
Variables	ESCC (N = 479)	Control (N = 479)	ESCC (N = 343)	ESCC (N = 288)
Gender
Female	109	109	87	79
Male	370	370	256	209
Age (years) (M ± SD)	59.92 ± 9.34	59.61 ± 8.84	58.39 ± 8.83	58.28 ± 8.84
Size of tumor (cm)
≤3	101		98	89
4–5	160		158	130
≥6	89		87	69
Unknown	129		0	0
Depth of tumor invasion
Tis	8		8	5
T1	29		29	24
T2	45		45	39
T3	239		239	216
T4	22		22	4
Unknown	136		0	0
Regional lymph node metastasis
N0	178		178	150
N1	103		103	88
N2	40		40	34
N3	22		22	16
Unknown	136		0	0
Distant metastasis
M0	337		337	288
M1	6		6	0
Unknown	136		0	0
Tumor location
Upper thoracic	56		27	19
Middle thoracic	251		191	158
Lower thoracic	143		125	111
Unknown	29		0	0
TNM classification
0	8		8	4
I	42 (3)^a		39	35
II	156 (18)^a		138	124
III	185 (33)^a		152	125
IV	20 (14)^a		6	0
Unknown	68		0	0
Radiotherapy after surgery
No			204	204
Yes			84	84
Unknown			55	0
Chemotherapy after surgery
No			207	207
Yes			81	81
Unknown			55	0

All associations are significant at P < 0.05
ESCC esophageal squamous cell carcinoma, SNP single nucleotide polymorphism, M mean, SD standard deviation
^aData shown in parentheses represent patients without tumor resection

ISSN: 1471-2407