Endoscopic polypectomy for malignant polyps: Should tumor location (right versus left side) guide clinical decisions?

Abstract

Background: Current guidelines consider endoscopic resection appropriate treatment for malignant colon polyps with negative margins, low-grade histology, and no lymphovascular invasion. While increasing literature demonstrates a worse prognosis for advanced stage right- versus left-sided colon cancers after curative treatment, there is paucity of data regarding prognostic effect of location in patients undergoing endoscopic resection of T1 polyps. We hypothesized the more aggressive biologic behavior observed in advanced right-sided cancers would be similarly represented in malignant polyps, and this location would be associated with lower overall survival. Methods: The National Cancer Database was queried for adults with T1NxMx tumors who underwent endoscopic polypectomy (2004–2017). Patients with positive margins or without follow-up information were excluded. Results: A total of 2,337 patients met inclusion criteria; 22% had right-sided polyps. Endoscopically excised proximal tumors were more common in elderly, and those with public insurance and more comorbidities (all P 92% without lymphovascular invasion, and 100% without tumor deposits. Univariate analysis showed 73% vs 86% 5-year overall survival for right versus left polyps (P