Table 4.

Assignment in Cox regression analysis

Factors	Variables	Assignment
Gender	X1	Male = 1, female = 2
Age (yr)	X2	< 60 = 1, ≥ 60 = 2
Tumor size (cm)	X3	< 2 = 1, ≥ 2 = 2
T staging	X4	T1/T2 = 1, T3 = 2
N staging	X5	N0 = 1, N1 = 2
M staging	X6	M0 = 1, M1 = 2
Differentiation	X7	High/medium = 1, low = 2
Nerve involvement	X8	No = 1, yes = 2
Vascular invasion	X9	No = 1, yes = 2
Smoking history	X10	No = 1, yes = 2
History of alcoholism	X11	No = 1, yes = 2
HULC	X12	< 4.661 = 1, ≥ 4.661 = 2