Table 3 Univariate and multivariate analysis of DFS

Gender

0.570 (0.458–0.709)

< 0.001

0.665 (0.496–0.892)

0.006

Age (year)

1.018 (1.007–1.029)

0.002

1.012 (1.001–1.023)

0.039

Tumor size (cm)

1.402 (1.278–1.538)

< 0.001

1.232 (1.089–1.394)

0.001

Smoking history

1.537 (1.258–1.877)

< 0.001

1.026 (0.780–1.348)

0.856

8^th TNM stage

1.938 (1.570–2.393)

< 0.001

1.386 (0.997–1.928)

0.052

Visceral pleural invasion

1.333 (1.088–1.631)

0.005

1.053 (0.799–1.373)

0.709

 Squamous cell carcinoma

Ref

Ref

 Adenocarcinoma

0.782 (0.611–0.999)

0.049

1.222 (0.926–1.614)

0.157

 Others

0.946 (0.666–1.433)

0.905

1.179 (0.789–1.762)

0.422

Differentiation degree

1.559 (1.323–1.838)

< 0.001

1.338 (1.124–1.592)

0.001

Vascular invasion

1.982 (1.378–2.852)

< 0.001

1.474 (1.006–2.160)

0.047

 0–2

Ref

 3–5

0.627 (0.391–1.005)

0.052

0.730 (0.451–1.180)

0.199

 6–8

0.841 (0.545–1.297)

0.433

0.916 (0.590–1.423)

0.696

 9–11

0.737 (0.470–1.156)

0.183

0.826 (0.522–1.307)

0.413

 12–14

0.730 (0.463–1.151)

0.175

0.869 (0.545–1.385)

0.554

 > 14

0.759 (0.505–1.142)

0.186

0.665 (0.555–1.285)

0.431

Adjuvant chemotherapy

1.127 (0.858–1.481)

0.500

Thoracotomy or VATS

0.933 (0.763–1.141)

0.304

 0–2

Ref

Ref

 3–5

0.654 (0.464–0.922)

0.015

0.640 (0.452–0.906)

0.012

 6–8

0.680 (0.486–0.949)

0.024

0.658 (0.469–0.924)

0.016

 9–11

0.595 (0.418–0.847)

0.004

0.585 (0.407–0.839)

0.004

 > 11

0.627 (0.445–0.884)

0.008

0.557 (0.391–0.793)

0.001