Table 1 Frequency of MGMT promoter methylation and loss of expression in colorectal cancer
MGMT promoter methylationMGMT expression
Total examined, nMethylated (%)Total examined, nLoss (%)p Value
All cases920354 (38%)599224 (37%)
Sex
    Men410150 (37%)25091 (36%)
    Women510204 (40%)349133 (38%)
Tumour differentiation
    Well/moderate815311 (38%)519190 (37%)
    Poor8434 (40%)5422 (41%)
Non-mucinous tumours593211 (36%)393133 (34%)Referent
Mucinous 1–49% (no signet ring cell)18585 (46%)12359 (48%)0.005
Mucinous ⩾50% (no signet ring cell)8141 (51%)4416 (36%)
Signet ring cells 1–49%4613 (28%)3516 (46%)
Signet ring cells ⩾50%154 (27%)40
Location
    Right255103 (40%)17670 (40%)
    Left (excluding rectum)17562 (35%)12150 (41%)
    Rectum10737 (35%)6518 (28%)
  • Only a statistically significant p value is described.