Cancer Risk by Morphology of Lateral Spreading Tumors: A Meta-Analysis

It is well known that the morphology (e.g., granular vs. nongranular) of lateral spreading tumors (LSTs) is associated with the risk for submucosal invasion. Since en bloc resection is widely considered a prerequisite for endoscopic resection to be curative (without surgery) in cases of superficial submucosal invasion, a clear picture of the risk for submucosal invasion associated with various morphologies could guide the decision whether to perform en bloc resection (when locally available) or piecemeal resection.

Among nearly 3000 studies reviewed, data from 48 were pooled in a meta-analysis. The overall risk for submucosal invasion was 5% in lesions 10 to 19 mm in size, 9% in lesions 20 to 29 mm, and 17% in lesions ≥30 mm. The highest risk for cancer was in nongranular depressed lesions (32%), followed by granular lesions with a discrete nodule (11%), then nongranular lesions with flat elevated shape (5%), and lastly granular homogenous lesions (0.5%).