Table 4.
Urinary isothiocyanates in relation to risk of colorectal cancer by GST genotypes
| Cases n (%) | Controls n (%) | Crude OR*(95% CI) | Adjusted OR † (95% CI) | P for interaction‡ | |
|---|---|---|---|---|---|
| GSTM1 | |||||
| GSTM1 non-null, undetectable ITC | 19 (23) | 31 (19) | 1.00 | 1.00 | |
| GSTM1 non-null, detectable ITC | 63 (77) | 135 (81) | 0.59 (0.25–1.39) | 0.49 (0.19–1.25) | |
| GSTM1 null, undetectable ITC | 23 (25) | 26 (18) | 1.00 | 1.00 | |
| GSTM1 null, detectable ITC | 68 (75) | 121 (82) | 0.56 (0.21–1.46) | 0.53 (0.15–1.93) | 0.42 |
| GSTT1 | |||||
| GSTT1 non-null, undetectable ITC | 32 (25) | 39 (19) | 1.00 | 1.00 | |
| GSTT1 non-null, detectable ITC | 95 (75) | 162 (81) | 0.63 (0.33–1.20) | 0.56 (0.28–1.13) | |
| GSTT1 null, undetectable ITC | 10 (22) | 18 (16) | 1.00 | 1.00 | |
| GSTT1 null, detectable ITC | 36 (78) | 94 (84) | 1.07 (0.32–3.57) | 0.86 (0.17–4.43) | 0.36 |
| GSTP1 | |||||
| GSTP1 AA, undetectable ITC | 21 (21) | 24 (15) | 1.00 | 1.00 | |
| GSTP1 AA, detectable ITC | 78 (79) | 138 (85) | 0.53 (0.22–1.30) | 0.58 (0.22–1.48) | |
| GSTP1 AG/GG, undetectable ITC | 21 (28) | z33 (22) | 1.00 | 1.00 | |
| GSTP1 AG/GG, detectable ITC | 53 (72) | 118 (78) | 0.57 (0.25–1.31) | 0.47 (0.19–1.17) | 0.09 |
*
Based on conditional logistic regression, using matched sets as strata.
†
Further adjusted for age at blood draw, hours of fasting before blood draw, processed meat (density, g/kcal/d), ethanol (g/d), obesity, and history of colorectal cancer screening.
‡
Values based on adjusted models, with urinary isothiocyanates, adjusted for creatinine, as a continuous variable.