In colon canser, the incidence of metastasis in the pericolic lymph nodes (LNs) located along the bowel and marginal artery is high. The optimal extent of bowel resection is closely associated with how we define 'regional' pericolic LNs, which should be resected because of the risk of metastasis. However, there are no standardised criteria for 'regional' LNs in the pericolic area.