Table 6.

Effect of polymorphism in selected genes on the effect of lifelong amount of tobacco smoked

GSTM1
+/+ or −/+−/−
Never-smokers1*0.8
Medium3.11.8
High2.93.2
Controls (%)105 (37%)184 (64%)

CYP1A1*2A
T/T
T/C
C/C
Never-smokers1*1.70.5
Medium2.03.83.7
High4.83.66.0§
Controls (%)53 (19%)155 (54%)78 (27%)
CYP1A1*2C
Ile/Ile
Ile/Val
Val/Val
Never-smokers1*0.9NA
Medium1.63.01.8
High3.82.52.5
Controls (%)213 (74%)208 (73%)33 (12%)
  • Abbreviation: NA, not applicable.

  • * Reference category.

  • P < 0.05.

  • Six controls but no cases occurred in this stratum.