Endoscopic Treatment of T1 Colorectal Cancer

SIMPLE SUMMARY: Endoscopic resection of early-stage colorectal cancer is sufficient if histopathology indicates a low risk for lymph-node metastasis. Among the factors associated with lymph-node metastasis, tumor infiltration depth into the submucosal layer seems to carry the lowest risk, particularly in the absence of other risk factors. Unfortunately, with current resection techniques, the quantity and quality of the submucosal layer are often insufficient. Thus, histopathology may become unreliable, and unnecessary surgery may result. A resection strategy using novel devices designed for endoscopic resection of a maximum quantity and quality of the submucosal layer should provide an advantage. ABSTRACT: Commonly accepted criteria for curative resection of T1 colorectal cancer include R0 resection with horizontal and vertical clear margins (R0), absence of lympho-vascular or vessel infiltration (L0, V0), a low to moderate histological grading (G1/2), low tumor cell budding, and limited (<1000 µm) infiltration into the submucosa. However, submucosal infiltration depth in the absence of other high-risk features has recently been questioned as a high-risk situation for lymph-node metastasis. Consequently, endoscopic resection techniques should focus on the acquisition of qualitatively and quantitively sufficient submucosal tissue. Here, we summarize the current literature on lymph-node metastasis risk after endoscopic resection of T1 colorectal cancer. Moreover, we discuss different endoscopic resection techniques with respect to the quality of the resected specimen.