Table 1 Patient characteristics in overall cohort.

Age, Mean ± SD

63.23 ± 17.50

71.49 ± 12.97

57.91 ± 17.98

< 0.001

Sex, n(%)

0.426

Female

501 (55.42)

202 (57.06)

299 (54.36)

Male

403 (44.58)

152 (42.94)

251 (45.64)

Race, n(%)

0.110

Black

86 (9.51)

42 (11.86)

44 (8.00)

Other

161 (17.81)

66 (18.64)

95 (17.27)

White

657 (72.68)

246 (69.49)

411 (74.73)

T stage, n(%)

< 0.001

T1-2

149 (16.48)

26 (7.34)

123 (22.36)

T3-4

584 (64.60)

176 (49.72)

408 (74.18)

TX

171 (18.92)

152 (42.94)

19 (3.45)

N stage, n(%)

< 0.001

N+

465 (51.44)

145 (40.96)

320 (58.18)

N0

323 (35.73)

112 (31.64)

211 (38.36)

NX

116 (12.83)

97 (27.40)

19 (3.45)

Radiation, n(%)

< 0.001

No evidence

353 (39.05)

241 (68.08)

112 (20.36)

Yes

551 (60.95)

113 (31.92)

438 (79.64)

Chemotherapy, n(%)

0.015

No evidence

791 (87.50)

298 (84.18)

493 (89.64)

Yes

113 (12.50)

56 (15.82)

57 (10.36)

Neck dissection, n(%)

< 0.001

No

521 (57.63)

347 (98.02)

174 (31.64)

Yes

383 (42.37)

7 (1.98)

376 (68.36)

Bone metastases, n(%)

0.468

No evidence

546 (60.40)

209 (59.04)

337 (61.27)

Yes

358 (39.60)

145 (40.96)

213 (38.73)

Brain metastases, n(%)

0.004

No evidence

843 (93.25)

320 (90.40)

523 (95.09)

Yes

61 (6.75)

34 (9.60)

27 (4.91)

Liver metastases, n(%)

< 0.001

No evidence

840 (92.92)

314 (88.70)

526 (95.64)

Yes

64 (7.08)

40 (11.30)

24 (4.36)

Lung metastases, n(%)

0.122

No evidence

247 (27.32)

86 (24.29)

161 (29.27)

Yes

657 (72.68)

268 (75.71)

389 (70.73)

DLN metastases, n(%)

0.245

No evidence

868 (96.02)

337 (95.20)

531 (96.55)

Yes

36 (3.98)

17 (4.80)

19 (3.45)

Number of involved

site, n(%)

< 0.001

1

683 (75.55)

232 (65.54)

451 (82.00)

2

184 (20.35)

100 (28.25)

84 (15.27)

3

33 (3.65)

20 (5.65)

13 (2.36)

4

4 (0.44)

2 (0.56)

2 (0.36)