Table 4 Risk of colon cancer associated with mismatch repair genotype, by smoking and microsatellite instability (MSI) status*
ExposureNever smoked, or not recentlySmoker ⩽2 years of referentp Interaction
GenotypeCases NoControls NoOR (95% CI)Cases NoControls NoOR (95% CI)
MSI-positive tumoursMSI-positive tumours
MLH1 -93G>A
    GG8110041 (referent)231681.78 (1.09 to 2.94)0.27
    GA505701.12 (0.77 to 1.61)171181.89 (1.08 to 3.32)
    AA19833.00 (1.72 to 5.22)3231.83 (0.53 to 6.29)
MLH1 Ile219Val (655A>G)
    Ile/Ile807821 (referent)201561.30 (0.77 to 2.20)0.56
    Ile/Val607140.83 (0.58 to 1.18)201311.57 (0.92 to 2.65)
    Val/Val101640.59 (0.30 to 1.17)3231.31 (0.38 to 4.47)
MSH6 Gly39Glu (116G>A)
    Gly/Gly8811201 (referent)332221.95 (1.27 to 3.00)0.12
    Gly/Glu574801.48 (1.04 to 2.10)10781.67 (0.83 to 3.37)
    Glu/Glu5521.25 (0.48 to 3.21)0100.00 Undefined
MSI-negative tumoursMSI-negative tumours
MLH1 -93G>A
    GG51610041 (referent)1021681.18 (0.90 to 1.54)0.005
    GA3075701.06 (0.89 to 1.26)391180.64 (0.44 to 0.93)
    AA46831.09 (0.75 to 1.60)5230.43 (0.16 to 1.15)
MLH1 Ile219Val (655A>G)
    Ile/Ile4177821 (referent)641560.76 (0.56 to 1.05)0.09
    Ile/Val3657140.97 (0.82 to 1.16)611310.88 (0.63 to 1.22)
    Val/Val871641.03 (0.77 to 1.38)21231.78 (0.97 to 3.27)
MSH6 Gly39Glu (116G>A)
    Gly/Gly55611201 (referent)1012220.90 (0.70 to 1.17)0.99
    Gly/Glu2864801.19 (0.99 to 1.42)41781.06 (0.71 to 1.57)
    Glu/Glu26520.97 (0.60 to 1.58)4100.79 (0.24 to 2.57)
  • *Adjusted for age, sex, race and centre.