Table 2 Univariate and multivariate analyses of OS in locally advanced OSCC patients

 Female

Ref

 Male

1.034 (0.908–1.179)

0.612

Age

1.024 (1.014–1.035)

< 0.001

1.023 (1.012–1.033)

< 0.001

  < 2

Ref

Ref

  ≥ 2

1.389 (1.087–1.776)

0.009

1.458 (1.137–1.871)

0.003

 No

Ref

 Yes

1.284 (0.904–1.824)

0.163

pT

< 0.001

< 0.001

 T1

Ref

Ref

 T2

2.317 (1.424–3.771)

0.001

2.128 (1.303–3.477)

0.003

 T3

2.869 (1.79–4.598)

0

3.157 (1.945–5.124)

0

 T4

4.317 (2.728–6.831)

0

4.316 (2.674–6.966)

0

pN

.073

.065

 N0

Ref

Ref

 N1

0.641 (0.445–0.924)

0.017

1.031 (0.701–1.517)

0.876

 N2

0.825 (0.618–1.101)

0.192

1.358 (0.99–1.864)

0.058

 N3

1.078 (0.656–1.773)

0.766

1.685 (1.01–2.811)

0.046

 III

Ref

Ref

 IV

1.526 (1.863–1.251)

< 0.001

1.358 (0.99–1.864)

0.058

 No

Ref

 Yes

1.428 (0.778–2.618)

0.250

Tumor differentation

0.224

 Well differentiated

Ref

 Moderately differentiated

1.385 (0.856–2.241)

0.184

 Poorly differentiated

2.581 (0.452–14.724)

0.286

  < 20 mm

Ref

  ≥ 20 mm

1.385 (0.856–2.241)

0.184

Number of Positive Nodes

0.002

0.009

 0

Ref

Ref

 1–2

1.483 (1.112–1.979)

0.007

1.357 (1.013–1.819)

0.041

 3–4

1.725 (1.238–2.402)

0.001

1.549 (1.106–2.171)

0.011

  ≥ 5

1.782 (1.203–2.64)

0.004

1.786 (1.202–2.653)

0.004

 No

Ref

 Yes

2.581 (0.452–14.724)

0.286

Primary Tumor Site

0.245

 Tongue

Ref

 Floor of mouth

2.625 (0.726–9.486)

0.141

 Other

1.306 (0.939–1.817)

0.113

 No

Ref

 Yes

2.377 (0.583–9.689)

0.227

 No

Ref

 Yes

1.244 (0.887–1.743)

0.206

  < 5 mm

Ref

  ≥ 5 mm

1.397 (0.766–2.547)

0.276

SII

  < 535.5

Ref

Ref

  ≥ 535.5

1.724 (1.354–2.194)

< 0.001

1.599 (1.25–2.047)

< 0.001

  < 2.8

Ref

Ref

  ≥ 2.8

1.774 (1.09–2.885)

0.021

2.243 (0.751–6.704)

0.148

  < 162.5

Ref

Ref

  ≥ 162.5

2.472 (1.127–5.424)

0.024

1.204 (0.854–1.699)

0.289