Table 4.

Associations between polymorphisms in MGMT, XPD, and XPG and risk of colorectal polyps stratified by age

Diagnostic groupEnzymeGenotypeAge (y)
Pinteraction (age × genotype)
<60
≥60
CasesControlsOR* (95% CI)CasesControlsOR* (95% CI)
Adenomatous polyps onlyMGMTHomozygous wt1332491.00 (Reference)1171092.38 (1.65-3.44)
Heterozygous651410.96 (0.65-1.43)52621.43 (0.90-2.26)
Homozygous variant11420.54 (0.26-1.11)17122.78 (1.18-6.52)0.09
XPDHomozygous wt571281.00 (Reference)52591.92 (1.14-3.25)
Heterozygous1012221.05 (0.69-1.60)100992.37 (1.50-3.75)
Homozygous variant51821.39 (0.83-2.32)34243.77 (1.94-7.35)0.75
XPGHomozygous wt1272471.00 (Reference)1201062.34 (1.62-3.38)
Heterozygous661560.94 (0.64-1.38)59701.80 (1.16-2.79)
Homozygous variant16300.99 (0.49-2.00)772.13 (0.69-6.56)0-82
Hyperplastic polyps onlyMGMTHomozygous wt782491.00 (Reference)361091.29 (0.78-2.14)
Heterozygous501411.32 (0.84-2.09)23621.18 (0.66-2.11)
Homozygous variant6420.51 (0.20-1.27)1120.37 (0.04-3.11)0.64
XPDHomozygous wt371281.00 (Reference)21591.16 (0.59-2.27)
Heterozygous732221.03 (0.63-1.68)25990.86 (0.46-1.61)
Homozygous variant25821.04 (0.56-1.96)14242.54 (1.10-5.83)0.16
XPGHomozygous wt802471.00 (Reference)421061.34 (0.83-2.16)
Heterozygous531561.13 (0.73-1.75)15700.76 (0.39-1.47)
Homozygous variant3300.20 (0.05-0.91)371.09 (0.26-4.63)0-07
Adenomatous + hyperplastic polypsMGMTHomozygous wt342491.00 (Reference)371093.07 (1.73-5.44)
Heterozygous131410.87 (0.42-1.80)22622.43 (1.25-4.75)
Homozygous variant10421.71 (0.72-4.05)6124.55 (1.39-14.87)0.99
XPDHomozygous wt161281.00 (Reference)28593.46 (1.60-7.50)
Heterozygous332221.24 (0.61-2.49)26992.51 (1.19-5.32)
Homozygous variant8820.86 (0.33-2.22)10244.84 (1.72-13.68)0.54
XPGHomozygous wt342471.00 (Reference)371062.85 (1.60-5.08)
Heterozygous221561.35 (0.73-2.51)22702.67 (1.34-5.30)
Homozygous variant1300.25 (0.03-1.98)678.38 (2.33-30.13)0.07
  • * Multivariate adjusted for sex, BMI, kcal, alcohol intake, dietary fiber, regular NSAIDs use, hormone replacement therapy and pack-years of smoking.

  • Heterozygotes: L-I/F-I and L-I/L-V; homozygous variants: F-I/F-I, F-I/L-V or L-I/F-V, F-I/FV, L-V/L-V, L-V/F-V, and F-V/F-V.

  • Heterozygotes: D-K/N-K, D-K/D-Q, D-K/N-Q, or N-K/D-Q; homozygous variant: N-K/N-K, N-K/N-Q, D-Q/D-Q, D-Q/N-Q, and N-Q/N-Q.