Table 4 Cox regression analyses of prognostic variables for OS in surgery patients

Age

1.020 (1.000–1.040)

0.036

1.018 (1.000–1.037)

0.046

Race

0.831 (0.496–1.390)

0.484

Sex

1.040 (0.758–1.420)

0.824

Year

0.947 (0.690–1.300)

0.739

Lateral

1.050 (0.946–1.160)

0.365

Procedure

0.907

 Sublobectomy

1

 Lobectomy

0.953 (0.689–1.318)

0.772

 Pneumonectomy

1.119 (0.483–2.592)

0.794

Number of examined lymph nodes

0.348

 ≤ 6

1

 ≥ 7

1.031 (0.715–1.486)

0.872

 Unknown

1.335 (0.876–2.034)

0.179

Number of positive lymph nodes ≥ 3 or unknown vs ≤ 2

1.510 (1.100–2.070)

0.010

1.447 (1.048–1.998)

0.025

T stage

0.022

 T1

1

1

 T2

1.406 (0.979–2.021)

0.065

1.325 (0.919–1.910)

0.132

 T3/T4

1.718 (1.154–2.557)

0.008

1.708 (1.135–2.571)

0.010

Radiation

0.640 (0.466–0.879)

0.006

0.684 (0.478–0.981)

0.039

Chemotherapy

0.684 (0.462–1.010)

0.059

0.784 (0.505–1.217)

0.278