Table 1.

Demographic characteristics among NSCLC cases and controls

CharacteristicsOverall
Male
Female
Cases (n = 1,900)Controls (n = 1,458)PCases (n = 981)Controls (n = 638)PCases (n = 919)Controls (n = 820)P
Age (mean ± SD)65 ± 10.858 ± 12.2<0.0166.0 ± 10.260.0 ± 12.9<0.0164.1 ± 11.057.3 ± 11.5<0.01
Gender, n (%)
    Female919 (48.8%)820 (56.2%)<0.01
    Male981 (51.6%)638 (43.8%)
Smoking, n (%)
    Never177 (9.3%)517 (35.5%)<0.0169 (7.0%)195 (30.6%)<0.01108 (11.8%)322 (39.3)<0.01
    Ex-smoker989 (52.1%)656 (45.0%)553 (56.4%)339 (53.1)436 (47.4%)317 (38.7%)
    Current smoker734 (38.6%)285 (19.6%)359 (36.6%)104 (16.3)375 (40.8%)181 (20.1%)
    Years since quit (median)*,12 (1-59)18 (1-65)<0.0114 (1-59)20 (1-65)<0.0112 (1-55)17 (1-59)<0.01
    Pack-years50 (0.1-231)25 (0.1-218)<0.0158 (0.2-231)29 (0.1-210)<0.0144 (0.02-210)21 (0.03-218)<0.01
Tumor stage (%)
    I and II48.6%49.0%48.0%
    III and IV51.3%51.0%52.0%
Cell type (%)
    Adenocarcinoma56.6%50.8%62.8%
    Squamous cell carcinoma23.3%29.0%17.2%
    Others20.1%20.2%20.0%
  • NOTE: Continuous variables tested with the Student's t test; categorical variables tested using the χ2 test.

  • * Ex-smokers only.

  • Median (range), tested by nonparametric Wilcoxon's rank sum test.