Table 1 Frequency of MGMT promoter methylation and loss of expression in colorectal cancer.
| MGMT promoter methylation | MGMT expression | ||||
|---|---|---|---|---|---|
| Total examined, n | Methylated (%) | Total examined, n | Loss (%) | p Value | |
| All cases | 920 | 354 (38%) | 599 | 224 (37%) | |
| Sex | |||||
| Men | 410 | 150 (37%) | 250 | 91 (36%) | |
| Women | 510 | 204 (40%) | 349 | 133 (38%) | |
| Tumour differentiation | |||||
| Well/moderate | 815 | 311 (38%) | 519 | 190 (37%) | |
| Poor | 84 | 34 (40%) | 54 | 22 (41%) | |
| Non‐mucinous tumours | 593 | 211 (36%) | 393 | 133 (34%) | Referent |
| Mucinous 1–49% (no signet ring cell) | 185 | 85 (46%) | 123 | 59 (48%) | 0.005 |
| Mucinous ⩾50% (no signet ring cell) | 81 | 41 (51%) | 44 | 16 (36%) | |
| Signet ring cells 1–49% | 46 | 13 (28%) | 35 | 16 (46%) | |
| Signet ring cells ⩾50% | 15 | 4 (27%) | 4 | 0 | |
| Location | |||||
| Right | 255 | 103 (40%) | 176 | 70 (40%) | |
| Left (excluding rectum) | 175 | 62 (35%) | 121 | 50 (41%) | |
| Rectum | 107 | 37 (35%) | 65 | 18 (28%) | |
Only a statistically significant p value is described.