Table 1. Demographic information.

Characteristics	Cases (n = 602)	Controls (n = 602)	P value
Age (y)*	60.6±10.7	59.5±12.9	0.087
Gender, (n (%))
Male	438 (72.8)	409 (67.9)	0.067
Hypertension, (n (%))
Yes	172 (28.6)	181 (30.1)	0.569
Yes	61(10.1)	76(12.6)	0.173
Smoking, (n (%))
Smokers	128(21.3)	94 (15.6)	0.012
Residence, (n (%))
Urban	244 (47.4)	271 (52.0)	0.116
Tumor differentiation (n (%))
Depth of tumor infiltration (n (%))
Lymph node metastasis (n (%))
Localization (n (%))
Noncardia	336(55.8)

* Median (25th-75th percentiles).