Table 4 Combinations of CYP1A1 and GST polymorphisms and colorectal cancer risk
| Â | Â | Number (%) | Â | Â | |
|---|---|---|---|---|---|
Combination of genotypes | Â | Cases | Controls | OR (95% CI)* | Pfor interaction |
CYP1A1*2A | GSTM1 | Â | Â | Â | Â |
   0†| Non-null | 122 (17.8) | 135 (17.4) | 1.00 (referent) |  |
   ≥1 | Non-null | 206 (30.1) | 221 (28.4) | 1.02 (0.74-1.40) | 0.34 |
   0 | Null | 161 (23.5) | 170 (21.9) | 1.01 (0.72-1.42) |  |
   ≥1 | Null | 196 (28.6) | 252 (32.4) | 0.84 (0.61-1.15) |  |
CYP1A1*2A | GSTT1 | Â | Â | Â | Â |
   0†| Non-null | 147 (21.5) | 158 (20.3) | 1.00 (referent) |  |
   ≥1 | Non-null | 200 (29.2) | 277 (35.6) | 0.75 (0.56-1.01) | 0.06 |
   0 | Null | 136 (19.9) | 147 (18.9) | 0.93 (0.67-1.30) |  |
   ≥1 | Null | 202 (29.5) | 196 (25.2) | 1.07 (0.79-1.45) |  |
CYP1A1*2A | GSTT1 + GSTM1 | Â | Â | Â | Â |
   0†| Non-null | 203 (29.6) | 222 (28.5) | 1.00 (referent) |  |
   ≥1 | Non-null | 299 (43.6) | 367 (47.2) | 0.88 (0.69-1.13) | 0.51 |
   0 | Null | 80 (11.7) | 83 (10.7) | 0.99 (0.68-1.43) |  |
   ≥1 | Null | 103 (15.0) | 106 (13.6) | 1.03 (0.73-1.44) |  |
CYP1A1*2C | GSTM1 | Â | Â | Â | Â |
   0†| Non-null | 187 (27.3) | 207 (26.6) | 1.00 (referent) |  |
   ≥1 | Non-null | 141 (20.6) | 149 (19.2) | 1.06 (0.78-1.45) | 0.29 |
   0 | Null | 231 (33.7) | 254 (32.6) | 0.98 (0.75-1.29) |  |
   ≥1 | Null | 126 (18.4) | 168 (21.6) | 0.83 (0.60-1.13) |  |
CYP1A1*2C | GSTT1 | Â | Â | Â | Â |
   0†| Non-null | 214 (31.2) | 239 (30.7) | 1.00 (referent) |  |
   ≥1 | Non-null | 133 (19.4) | 196 (25.2) | 0.76 (0.56-1.01) | 0.02 |
   0 | Null | 204 (29.8) | 222 (28.5) | 0.98 (0.75-1.29) |  |
   ≥1 | Null | 134 (19.6) | 121 (15.6) | 1.23 (0.90-1.69) |  |
CYP1A1*2C | GSTT1 + GSTM1 | Â | Â | Â | Â |
   0†| Non-null | 300 (43.8) | 337 (43.3) | 1.00 (referent) |  |
   ≥1 | Non-null | 202 (29.5) | 252 (32.4) | 0.90 (0.70-1.15) | 0.39 |
   0 | Null | 118 (17.2) | 124 (15.9) | 1.00 (0.74-1.36) |  |
   ≥1 | Null | 65 (9.5) | 65 (8.4) | 1.13 (0.77-1.66) |  |