Table 2 Univariate analysis associated to the level V metastasis

Age (year)

40.21 ± 9.34

45.6 ± 13.63

0.159

Gender

1.000

 Male

4 (28.6)

22 (38)

 Female

10 (71.4)

58 (62)

Tumor size (USG)

20.29 ± 11.97

15.28 ± 9.7

0.089

The largest LN size (USG)

15.21 ± 3.91

14.56 ± 7.81

0.635

LN/tumor size ratio (USG)

1.07 ± 0.77

1.26 ± 0.94

0.485

Multi-level suspicious LNs (USG)

10 (71.4)

33 (41.3)

0.037

Tumor location

0.549

 Upper

7 (50)

28 (35)

 Middle

7 (50)

50 (62.5)

 Lower

0

2 (2.5)

Multifocality

9 (64.3)

41 (51.3)

0.367

Bilaterality

6 (42.9)

31 (38.8)

0.772

Extrathyroidal extension

3 (21.4)

7 (8.8)

0.167

Tumor size (pathology)

19.57 ± 11.93

14.28 ± 7.06

0.128

Size of the largest metastatic focus (pathology)

17.43 ± 8.28

12.2 ± 8.66

0.039

Metastatic focus/tumor size ratio (pathology)

1.19 ± 0.96

1.05 ± 0.88

0.584

Extranodal extension

10 (71.4)

42 (52.5)

0.189

Stage

0.505

 I

12 (85.7)

59 (73.8)

 II

2 (14.3)

21 (26.2)

CLNM

14 (100)

65 (81.3)

0.116

 Level II

2 (14.3)

5 (6.3)

0.279

 Level III

0

15 (18.8)

0.116

 Level IV

1 (7.1)

3 (3.8)

0.481

 Level II and III

2 (14.3)

10 (12.5)

1.0

 Level II and IV

0

7 (8.8)

0.589

 Level III and IV

0

22 (27.5)

0.035

 Level II, III, and IV

9 (64.3)

18 (22.5)

0.003

 Total

16.93 ± 8.06

9.51 ± 6.66

< 0.001

 Level II

3.07 ± 2.34

1.19 ± 1.61

0.011

 Level III

3.93 ± 4.29

1.91 ± 1.69

0.105

 Level IV

1.93 ± 1.64

1.43 ± 1.64

0.293

Level VI

7.00 ± 4.19

4.96 ± 4.96

0.151

 Total

0.35 ± 0.16

0.25 ± 0.17

0.036

 Level II

0.52 ± 0.35

0.22 ± 0.29

0.001

 Level III

0.32 ± 0.23

0.25 ± 0.24

0.330

 Level IV

0.32 ± 0.32

0.19 ± 0.20

0.158

 Level VI

0.58 ± 0.32

0.51 ± 0.38

0.539

3-level with ≥ 2.5 metastatic LNs in level II

6 (42.9)

6 (7.5)

0.002

Less than 3-level with ≤ 2 metastatic LNs in level II

4 (28.6)

55 (68.8)

0.004