# The Outcome of Local Excision of Rectal Adenomas with High-Grade Dysplasia by Transanal Endoscopic Microsurgery: A Single-Center Experience

## TL;DR

This study examines the effectiveness of transanal endoscopic microsurgery for treating rectal adenomas with high-grade dysplasia and finds that tumor size is a key factor in predicting recurrence.

## Contribution

The study provides new insights into the risk of invasive cancer in high-grade dysplasia rectal polyps and identifies tumor size as a significant predictor of recurrence after surgery.

## Key findings

- 36% of patients with preoperative high-grade dysplasia had invasive carcinoma postoperatively.
- Tumor size greater than 5 cm was significantly associated with tumor recurrence (p = 0.03).
- Only 9.4% of patients with final high-grade dysplasia pathology experienced tumor recurrence.

## Abstract

Background: Local excision by transanal endoscopic microsurgery (TEM) is considered an acceptable treatment for rectal adenomas with high-grade dysplasia (HGD). This study aims to assess the likelihood of harboring an invasive carcinoma in preoperatively diagnosed HGD polyps and evaluate the risk factors for tumor recurrence in patients with final HGD pathology. Methods: Data from patients who underwent TEM procedures for adenomatous lesions with HGD from 2005 to 2018 at the Rabin Medical Center, Hasharon Hospital, were analyzed. Collected data included patient demographics, preoperative workup, tumor characteristics and postoperative results. Follow-up data including recurrence assessment and further treatments were reviewed. The analysis included two subsets: preoperative pathology of HGD (sub-group 1) and postoperative final pathology of HGD (sub-group 2) patients. Results: Forty-five patients were included in the study. Thirty-six patients had a preoperative diagnosis of HGD, with thirteen (36%) showing postoperative invasive carcinoma. Thirty-two patients had a final pathology of HGD, and three (9.4%) experienced tumor recurrence. Large tumor size (>5 cm) was significantly associated with recurrence (p = 0.03). Conclusions: HGD rectal polyps are associated with a significant risk of invasive cancer. Tumor size was a significant factor in predicting tumor recurrence in patients with postoperative HGD pathology. The TEM procedure is an effective first-line treatment for such lesions.