Is It Safe to Skip Surgery After Malignant Colorectal Polyp Removal?

TOPLINE:

Among patients with high-risk malignant colorectal polyps, 19% had residual disease, with rates of 25% in the immediate surgery group vs 9% in the nonoperative management group. The rate of rectum and sphincter preservation in the nonoperative surveillance group was over 90%, and all recurrences were successfully treated with salvage surgery or chemoradiotherapy.

METHODOLOGY:

• Although guidelines in the US recommend colorectal resection when a malignant colorectal polyp has high-risk features, some patients choose nonoperative management instead to avoid the associated averse effects and impact on quality of life. The safety of nonoperative management, however, remains unclear.
• A single-center cohort study conducted between 2015 and 2022 included 336 patients who underwent polypectomy in the colon (n = 226) or rectum (n = 110) and had at least one high-risk feature. High-risk features included positive margins, piecemeal resection with unclear margin, lymphovascular invasion, perineural invasion, poor differentiation, and tumor budding.
• The analysis compared rates of residual disease between those who had immediate surgery (62%) and nonoperative management (38%) following the removal of a malignant polyp, 15% of whom (n = 19) received systemic chemotherapy after polypectomy.
• Researchers also assessed the rates of distant metastasis between the two groups and the association between specific high-risk features and residual disease or post-treatment complications.

TAKEAWAY:

• In the overall population, 19% of patients had residual disease (63 of 336). Among the 208 patients who had immediate surgery, 25% (n = 51) had residual disease, including 9% (n = 19) with residual disease in the bowel wall and 19% (n = 39) in locoregional lymph nodes. Postoperative complications occurred in 12% of patients (n = 25) in the immediate surgery group, with 3% (n = 7) having complications considered grade 3 or higher.
• Among the 128 patients who received nonoperative surveillance, 9% (n = 12) developed recurrence during surveillance, 6% (n = 7) in the bowel wall and 4% (n = 5) in locoregional lymph nodes. All recurrences in the nonoperative surveillance group were successfully treated with either salvage surgery (n = 6) or chemoradiotherapy (n = 6).
• Among patients in the nonoperative group with a malignant polyp removed from the rectum, the rate of rectum preservation was 94% (74 of 79 patients); the sphincter preservation rate was 91% for tumors < 5 cm from the anal verge.
• Distant metastases occurred in 2% of all patients across both groups.

IN PRACTICE:

"The risk of residual disease after the removal of a malignant colorectal polyp with [high-risk features] is considerable, but nonoperative management offers the potential for organ preservation, with the availability of effective salvage options if rectal cancer is detected," the authors of the study concluded.

SOURCE:

The study, led by Thikhamporn Tawantanakorn, MD, and Martin R. Weiser, MD, of Memorial Sloan Kettering Cancer Center in New York City, was published online in JCO Oncology Advances.

LIMITATIONS:

The researchers noted several limitations, including variable follow-up among patients and challenges in assessing polypectomy histology, particularly after piecemeal resection, which limited evaluation of certain high-risk features such as tumor budding. Additionally, as the study was conducted at a specialized cancer center with dedicated gastrointestinal pathology and radiology services and readily available office endoscopy, the results may not be fully generalizable to less specialized centers.

DISCLOSURES:

Jinru Shia, MD, reported receiving consulting fees from Paige.AI and research funding through their institution. Andrea Cercek, MD, disclosed consulting roles with multiple pharmaceutical companies, including GlaxoSmithKline, Incyte, Merck, and others, as well as research funding from GlaxoSmithKline and Pfizer. Weiser reported receiving royalties as a section editor for UpToDate. Additional disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

A version of this article first appeared on Medscape.com.