Table 3.

Risk of left-sided advanced colorectal adenoma associated with cigarette smoking, and specific GSTM1, GSTT1, and GSTP1 polymorphisms

Never smokers
Ever smokers
Controls n (%)Cases n (%)OR (95% CI)*Controls n (%)Cases n (%)OR (95% CI)*P interaction
GSTM1
    +/+12 (4.4)18 (8.1)1.0 (reference)23 (6.1)40 (9.8)1.0 (reference)
    +/−110 (40.4)87 (39.6)0.5 (0.2-1.2)150 (39.7)150 (36.9)0.6 (0.3-1.0)
    −/−150 (55.2)115 (52.3)0.5 (0.2-1.1)205 (54.2)217 (53.3)0.6 (0.3-1.0)0.59
Ptrend = 0.2Ptrend = 0.1
    +/− and −/−260 (95.6)202 (91.9)0.5 (0.2-1.1)355 (93.9)367 (90.2)0.6 (0.3-1.0)0.79
GSTT1
    +/+83 (29.6)75 (33.2)1.0 (reference)149 (39.1)133 (31.2)1.0 (reference)
    +/−147 (52.5)107 (47.3)0.8 (0.5-1.2)176 (46.2)217 (50.8)1.4 (1.0-1.9)
    −/−50 (17.9)44 (19.5)1.0 (0.6-1.7)56 (14.7)77 (18.0)1.6 (1.0-2.4)0.12
Ptrend = 0.9Ptrend = 0.2
    +/− and −/−197 (70.4)151 (66.8)0.9 (0.6-1.3)232 (60.9)294 (58.8)1.4 (1.1-1.9)0.05
    GSTP1—I105V
    AA132 (48.5)97 (44.1)1.0 (reference)171 (44.1)173 (40.8)1.0 (reference)
    AG + GG140 (51.5)123 (55.9)1.2 (0.9-1.8)251 (56.9)251 (59.2)1.2 (0.9-1.6)0.79
    GSTP1—A114V
    CC238 (84.4)189 (81.1)1.0 (reference)324 (83.3)375 (87.2)1.0 (reference)
    CT + TT44 (15.6)44 (18.9)1.2 (0.8-2.0)65 (16.7)55 (12.8)0.7 (0.5-1.1)0.18
  • * Adjusted for age, race, and gender.