Residual Disease Risk in Early Colorectal Cancer with Positive Margins

In a retrospective study in Korea, researchers assessed risk for residual tumor in 265 patients with T1 colorectal cancer who had histologic positive resection margins after complete endoscopic resection. There were 213 who had additional surgery and 52 who did not because of surgical risk factors. In the surgery patients, 13 (6%) had residual tumor, and none of the variety of clinicopathological factors assessed were associated with residual disease; these included gender, colon versus rectal location, polypoid versus nonpolypoid shape, en bloc versus piecemeal resection, margin status (deep positive, lateral positive, or both positive), histologic grade of tumor, tumor budding, vascular invasion, and depth of submucosal invasion (SM1 vs. …