[Treatment of T1 colorectal cancer].

In case of suspicion of a T1 colorectal tumor, the tumor should not be biopsied but removed completely (so-called en-bloc resection). With more recent endoscopic techniques, T1 colorectal tumors can be more often radical resected. If at least one of the following four characteristics is present, there is a high-risk T1 colorectal tumor and it is recommended to consider surgical resection with adequate lymphadenectomy; poor differentiation, presence of (lymphatic) angioinvasion, high-grade tumor budding (grade 2-3) and a positive resection margin (where the malignant cells approach the cut edge to 0.1mm). The risk of recurrent disease after endoscopic resection of a high-risk T1 colorectal tumor without additional surgery is not well known. Scheduled surgery for bowel cancer at an early stage is associated with the same risk of a serious complication and/or death as scheduled surgery at a more advanced stage.