Table 2.

RR of TP53 and KRAS mutation for smoking status, cumulative tobacco consumption, and histology

TP53 mutated, n (%)TP53 Wild type, n (%)RR * (95% CI)KRAS mutated, n (%)KRAS Wild type, n (%)RR * (95% CI)
Smoking status
    Never smokers (n = 40)19 (47.5)21 (52.5)1 (reference)4 (10)36 (90)1 (reference)
    Ever smokers (n = 91)63 (70.8)26 (29.2)3.2 (0.7-16)16 (17.6) 75(82.4)0.9 (0.1-7.1)
    Former smokers (n = 27)15 (55.6)12 (44.4)1.7 (0.3-9.2)8 (29.6)19 (70.4)1.6 (0.2-13)
    Current smokers (n = 64)48 (77.4)14 (22.6)5.2 (1.0-27)8 (12.5)56 (87.5)0.6 (0.1-4.4)
    Total82 (63.6)47 (36.4)20 (15.3)111 (84.7)
Tobacco consumption (pack-years)
    0 (n = 40)19 (47.5)21 (52.5)1 (reference)4 (10)36 (90)1 (reference)
    <30 (n = 22)9 (40.9)13 (59.1)1.2 (0.2-6.7)7 (31.8)15 (68.2)1.7 (0.2-14)
    30-39 (n = 16)11 (73.3)4 (26.7)7.6 (1.0-61)4 (25)12 (75)1.3 (0.1-13)
    40-49 (n = 31)24 (80)6 (20)8.5 (1.3-56)5 (16.1)26 (83.9)0.7 (0.1-6.3)
    >50 (n = 22)19 (86.4)3 (13.6)13 (1.7-101)0 (0)22 (100)
Histology
    Adenocarcinoma (n = 47)20 (42.6)27 (57.4)1 (reference)10 (21.3)37 (78.7)1 (reference)
    SCC (n = 54)40 (76.9)12 (23.1)3.0 (1.1- 8.1)5 (9.2)49 (90.8)0.2 (0.07-1.0)
    ADC-SCC (n = 16)12 (75)4 (25)3.4 (0.9-13)4 (25)12 (75)1.1 (0.2-5.0)
    Others (n = 14)10 (71.4)4 (28.6)4.3 (1.1-17)1 (7.1)13 (92.9)0.3 (0.03-3.5)
  • * Multivariate analysis adjusting for (a) sex, age, and education for RR related to smoking status or tobacco consumption and (b) sex, age, education, and smoking status for RR related to histology.

  • Two cases were removed for the statistical analysis of TP53 mutation because no DNA has been amplified.

  • pack-years = number of years of smoking × average number of packs smoked/d.