Table 3 Univariate and Multivariate Cox proportional hazards analysis of various prognostic factors and their relationship to disease-free survival

Sex

Male/Female

0.960(0.775–1.188)

0.707

Age (years)

 ≤ 60/ > 60

1.213(1.018–1.446)

0.031

1.015(1.005–1.026)

0.003

1.015(1.005–1.026)

0.003

1.015(1.005–1.026)

0.003

Tumor location

Upper thoracic

1

Middle thoracic

1.031(0.793–1.341)

0.818

Lower thoracic

1.068(0.801–1.423)

0.655

Degree of differentiation

Well and Moderate/ Poor

1.556(1.161–2.085)

0.003

1.276(0.947–1.718)

0.109

1.306(0.971–1.757)

0.078

1.275(0.946–1.717)

0.110

LVI

No/Yes

1.733(1.447–2.077)

 < 0.001

1.248(1.025–1.518)

0.027

1.261(1.037–1.534)

0.020

1.245(1.022–1.515)

0.029

PNI

No/Yes

1.363(1.132–1.640)

0.001

1.079(0.890–1.308)

0.438

1.072(0.884–1.299)

0.482

1.076(0.887–1.305)

0.458

pN

N0

1

1

1

1

N1

1.813(1.462–2.247)

 < 0.001

1.667(1.331–2.087)

 < 0.001

1.615(1.290–2.023)

 < 0.001

1.660(1.324–2.080)

 < 0.001

N2

3.021(2.389–3.821)

 < 0.001

2.581(1.998–3.335)

 < 0.001

2.531(1.957–3.272)

 < 0.001

2.565(1.983–3.319)

 < 0.001

N3

4.882(3.529–6.753)

 < 0.001

3.900(2.760–5.512)

 < 0.001

3.852(2.721–5.452)

 < 0.001

3.881(2.744–5.489)

 < 0.001

CRM CAP criteria

R0/R1

1.803(1.331–2.443)

 < 0.001

1.575(1.157–2.145)

0.004

CRM RCP criteria

R0/R1

1.362(1.140–1.627)

0.001

1.130(0.942–1.355)

0.189

CRM three-tier criteria

 > 1 mm

1

1

0-1 mm

1.255(1.036–1.521)

0.020

1.044(0.859–1.270)

0.664

0 mm

1.945(1.424–2.655)

 < 0.001

1.601(1.166–2.199)

0.004

Adjuvant therapy

No/Yes

1.617(1.340–1.952)

 < 0.001

1.216(0.996–1.485)

0.055

1.231(1.009–1.503)

0.041

1.216(0.996–1.485)

0.055

Extranodal invasion^a

No/Yes

1.556(1.247–1.943)

 < 0.001