Characteristics N = 52

Gender Male 41

Female 11

Age (years) Mean 58.6 ± 11.7

Range 31 - 79

Differentiation Well 2

Moderate 14

Poor 36

Location of tumor Upper 13

Middle 14

Lower 25

Depth of invasion [7] T1 10

T2 10

T30

T4 32

Lymph node metastasis * N0 20

N1 10

N2 14

N3 8

Stage [8] I 15

II 10

III 24

VI 3