Table 1 Correlation analysis for KLK6 protein expression and clinico-pathological features of the combined HNSCC cohort

Age [years]

<58.62

50

30

0.128

≥58.62

43

39

Gender

male

69

60

0.035

female

24

9

Tumor size

T1/2

39

30

0.509

T3/4

53

39

missing¹

1

Lymph node status

N0

27

27

0.129

N+

65

42

missing¹

1

Distant metastasis

M0

87

67

0.287

M+

4

1

missing¹

2

1

Clinical stage

I/II

16

12

0.581

III/IV

76

57

missing¹

1

Pathological grade

G1/2

46

42

0.319

G3

29

21

missing¹

18

6

Smoking status

non-smoker

10

9

0.400

smoker²

82

58

missing¹

1

2

Alcohol consumption

non-drinker

8

9

0.219

drinker³

83

55

missing¹

2

5