| 
   
  | Variable | n | HR | 95% CI | p-value |  
  | Primary site of lung cancer
    Upper lobe | 17 | 3.21 | 0.23-43.81 | 0.3827 |  
  | Location of primary mass
    Subpleural area | 17 | 4.17 | 0.30-57.22 | 0.2847 |  
  | Serum KL-6 at diagnosis
    higher than the normal range (≥500U/ml) | 17 | 12.47 | 1.21-128.36 | 0.0339 |  
  | Serum LD at diagnosis
    higher than the normal range (>230IU/l) | 17 | 1.81 | 0.18-17.97 | 0.6110 |  | 
  
 | KL-6: Krebs von den Lungen-6; LD: Lactate Dehydrogenase; HR: Hazard Ratio;
 CI: Confidence Interval. | 
  
 | Table 3: Multivariate Cox proportional hazards regression analysis for the risk of
 death in the LC+CPFE group. |