Table 3 Univariate and multivariate analyses of risk factors for recurrence-free survival using a proportional hazard model

Sex

Male

2.171

1.293–3.647

0.002

Female

1

Age

1.028

0.998–1.058

0.065

BMI

0.944

0.871–1.

0.155

Smoking Index

1.001

1.000–1.001

< 0.001

1.000

1.000–1.001

0.006

VC (%)

0.984

0.970–0.998

0.029

0.985

0.971–0.999

0.032

FEV1/FVC (%)

0.965

0.945–0.986

0.001

COPD

No

1

Yes

1.806

1.134–2.874

0.013

Surgical procedure

Sublobar resection

1

Lobectomy

0.940

0.598–1.476

0.787

Tumor size

1.288

1.054–1.575

0.013

Histology

Adenocarcinoma

1

Squamous cell carcinoma

2.034

1.199–3.450

0.008

Other

3.146

1.426–6.942

0.005

Histologic grade

Well differentiated

1

1

Moderately differentiated

2.800

1.647–4.760

< 0.001

1.934

1.111–3.367

0.020

Poorly differentiated

3.605

1.933–6.722

< 0.001

2.026

1.048–3.915

0.036

Pleural invasion

Absent

1

1

Present

2.713

1.734–4.246

< 0.001

1.845

1.154–2.951

0.011

Emphysema

Absent

1

1

Present

2.807

1.749–4.504

< 0.001

2.122

1.173–3.839

0.013