Table 1 Frequency distribution of select characteristics by case–control status

From: A novel T-77C polymorphism in DNA repair gene XRCC1 contributes to diminished promoter activity and increased risk of non-small cell lung cancer

Variable Patients (n=1024) Controls (n=1118) P-value*
  No. (%) No. (%)  
Sex      0.124
 Male 723 70.6 755 67.5  
 Female 301 29.4 363 32.5  
Age (years)      0.390
40 76 7.4 81 7.2  
 41–50 202 19.7 203 18.2  
 51–60 304 29.7 363 32.5  
 61–70 349 34.1 389 34.8  
 >70 93 9.1 82 7.3  
Smoking status a      <0.0001
 No 396 38.7 590 52.8  
 Yes 628 61.3 528 47.2  
Pack-years value      <0.0001
27 220 35.0 313 59.3  
 >27 408 65.0 215 40.7  
Histological type
 Squamous-cell carcinoma 417 40.7    
 Adenocarcinoma 381 37.2    
 Othersb 226 22.1    
  1. *Two-sided χ2-test.
  2. aNon-smokers were defined as subjects who smoked <10 cigarettes lifetime.
  3. bOther includes undifferentiated cancer (n=82), bronchioalveolar carcinoma (n=98), and mixed cell carcinoma (n=46).