Detailed pathological analysis of the advancing edge of the tumour can effectively stratify clinical T4b colorectal cancer patients.

Only CRCs with tumour cell invasion into the muscular wall of the adjacent organs should be classified as pT4b, and it might be better to avoid 'the presence of tumour cells in fibrous adhesion' to define pathological T4b CRCs. In addition, the presence of a peritumoral abscess should be recorded as a predictor of better prognosis.