Surgery after Resection of Malignant Polyps: better safe than sorry?

Aims After resection of a malignant colorectal polyp, patients may be proposed for surgical treatment or surveillance, depending on the presence of cure criteria. The aim of this study was to compare the detection of metachronous lesions in patients with malignant polyps undergoing surgery versus surveillance.

Methods Retrospective cohort study including patients with endoscopic removal of malignant polyps. Patients were divided into 2 groups, according to the strategy defined in the oncology group consultation: surveillance (group 1) and surgery (group 2). The diagnosis of metachronous lesions during the follow-up period was the main outcome studied. A metachronous lesion was defined as the detection of adenoma/adenocarcinoma, 6 or more months after index colonoscopy.

Results 77 patients were included, 55.8% in group 1, 44.2% in group 2. Mean age was 65±11 years, 54.5% were male. In group 1, significantly more patients developed metachronous lesions compared to group 2 (66.7% vs 33.3%, p=0.036). The mean time to diagnosis of metachronous lesion was significantly shorter in group 1 (18.6±2.8 vs 36.0±5.6 months, p=0.004). In group 1, 32.1% of patients developed metachronous lesions in the same colonic segment as the endoscopic resection of the malignant polyp. In histological characterization, the two groups did not present statistically significant differences: low-grade dysplasia in 92.9% (group 1) and 85.7% (group 2); high-grade dysplasia in 7.1% (group 1) and 14.3% (group 2), p=0.457. No adenocarcinomas were detected during the follow-up period.

Conclusions Surgical approach was associated with a lower incidence of metachronous lesions, suggesting that a significant proportion of the risk of metachronous lesion occurs in the segment of the index lesion.

Publication History

Article published online:
27 March 2025