Table 1 Clinicopathological features of patients according to the presence and extent of ETE

Gender

0.814

  Female

466 (78.6%)

164 (80.4%)

14 (82.4%)

  Male

127 (21.4%)

40 (19.6%)

3 (17.6%)

Age (years, mean ± SD)

45.8 ± 11.7

46.0 ± 12.1

42.4 ± 14.0

0.482

Histologic variation

0.206

  Conventional

385 (64.9%)

154 (75.5%)

12 (70.6%)

  Follicular variant

194 (32.7%)

46 (22.5%)

5 (29.4%)

  Tall cell variant

2 (0.3%)

1 (0.8%)

0 (0%)

  Other

12 (2.0%)

3 (1.5%)

0 (0%)

Lymphatic invasion

8 (1.3%)

10 (4.9%)

4 (23.5%)

 < 0.001

Perineural invasion

4 (0.7%)

7 (3.4%)

2 (11.8%)

 < 0.001

Vascular invasion

1 (0.2%)

2 (1.0%)

2 (11.8%)

 < 0.001

LN metastasis

187 (31.5%)

96 (47.1%)

11 (64.7%)

 < 0.001

Lateral LN metastasis

24 (4.0%)

12 (5.9%)

2 (11.8%)

 < 0.001

BRAF mutation

117/191 (61.3%)

135/204 (66.2%)

33/39 (84.6%)

0.309 (a) 0.005 (b) 0.095 (c)

Extent of surgery

 < 0.001

  Total thyroidectomy

390 (65.8%)

156 (76.5%)

15 (88.2%)

  Lobectomy

201 (33.9%)

41 (20.1%)

2 (11.8%)

  Wide isthmusectomy

2 (0.3%)

7 (3.4%)

0 (0%)