Table 1 Summary of clinicopathologic, primary treatment, postoperative recurrence, distant metastasis, and survival time variables of the overall dataset (n=581).

Sex

Male

278 (47.8%)

Female

303 (52.2%)

Age

< 41 years

41 (7.1%)

41 – 60 years

241 (41.4%)

>60 years

299 (51.5 %)

Tumor location

Oral tongue

258 (44.4%)

Floor of mouth

53 (9.1%)

Buccal mucosa

64 (11.0%)

Alveolar ridge

110 (18.9%)

Hard palate

13 (2.2%)

Lip

67 (11.6%)

Retromolar trigone

16 (2.8%)

T stage

T1

98 (16.9%)

T2

194 (33.4%)

T3

100 (17.2%)

T4a

186 (32.0%)

T4b

3 (0.5%)

pN stage

N0

298 (51.3%)

N1

107 (18.4%)

N2a

25 (4.3%)

N2b

108 (18.6%)

N2c

38 (6.5%)

N3

5 (0.9%)

TNM stage

I

78 (13.4%)

II

109 (18.8%)

III

106 (18.2%)

IVa

279 (48.0%)

IVb

9 (1.6%)

Histologic grade

Well

387 (66.6%)

Moderate

165 (28.4%)

Poor

29 (5.0%)

Lymph node metastasis

Positive

283 (48.7%)

Negative

298 (51.3%)

Lymphovascular invasion

Positive

100 (17.2%)

Negative

481 (82.8%)

Perineural invasion

Positive

138 (23.8%)

Negative

443 (76.2%)

Margin

Positive

114 (19.6%)

Close

20 (3.4%)

Clear

447 (77.0%)

Extranodal extension

Positive

44 (7.6%)

Negative

537 (92.4%)

Primary treatment

Surgery only

150 (25.8%)

Surgery combines with radiotherapy

302 (52.0%)

Surgery combines with concurrence chemoradiotherapy

129 (22.2%)

Locoregional recurrence

Local recurrence

78 (13.4%)

No recurrence

503 (86.6%)

Post operative distant metastasis

Lung metastasis

29 (5.0%)

Bone metastasis

6 (1.0%)

No metastasis

546 (94.0%)

Overall survival time (Class)

0 – 12 months (Class 0)

154 (26.5%)

13 – 24 months (Class 1)

67 (11.5%)

25 – 36 months (Class 2)

33 (5.7%)

37 – 48 months (Class 3)

19 (3.3%)

49 – 60 months (Class 4)

6 (1.0%)

> 60 months (Class 5)

302 (52.0%)