Risk of Residual Cancer After Immediate Surgery or Nonoperative Management After Malignant Colorectal Polypectomy With High-Risk Features

PURPOSE National guidelines recommend colorectal resection when pathology from a malignant colorectal polyp reveals high-risk features (HRFs). However, some patients opt to avoid surgery because of concerns about associated morbidity and potential impacts on quality of life, despite the risk of residual disease. METHODS In this single-center cohort study of patients treated between 2015 and 2022, we retrospectively compared rates of residual disease between patients who underwent immediate surgery and patients managed nonoperatively after removal of a malignant polyp with HRFs. RESULTS Of 336 patients who underwent a polypectomy in the colon (n = 226) or rectum (n = 110) and had at least one HRF, 208 (62%) underwent immediate surgery and 128 (38%) were managed nonoperatively. Residual disease was identified in 63 patients (19%), either at the time of immediate surgery or during surveillance in the nonoperative group. In the immediate surgery group, 51 (25%) patients had residual disease, including 19 (9%) with residual disease in the bowel wall and 39 (19%) in locoregional lymph nodes (LNs). In the nonoperative cohort group, 12 (9%) developed recurrence after polypectomy during surveillance, including 7 (6%) in the bowel wall and 5 (4%) in locoregional LNs. In the nonoperative group, all recurrences after polypectomy were successfully treated with salvage surgery (n = 6) or chemoradiotherapy (n = 6). Distant metastases occurred in 2% of patients. CONCLUSION The risk of residual disease after removal of a malignant polyp with HRFs approaches 20%. Patients who are concerned about the potential morbidity of surgery and its impact on postoperative quality of life should be counseled about this risk, as well as the availability of effective salvage treatments after nonoperative surveillance.