Predictors of rectal adenoma recurrence following transanal endoscopic surgery: a retrospective cohort study.

[BACKGROUND] Transanal endoscopic surgery is the treatment of choice in patients with rectal adenomas that cannot be removed by endoscopy. However, the risk of adenoma recurrence and optimal surveillance is not well defined. The objective of this study was to characterize the timing and frequency of rectal adenoma recurrence after removal by transanal endoscopic surgery and identify recurrence risk factors.

[METHODS] This was a retrospective cohort study of a large, single-center academic institution in Vancouver, BC, Canada. Consecutive patients between May 1, 2007 and September 30, 2016 with pathology-confirmed rectal adenoma treated by primary excision with transanal endoscopic surgery and at least 1 year of confirmed endoscopic follow-up were included. Main outcome measures were recurrence rates following TEM as well as risk factors for recurrence.

[RESULTS] 297 patients met inclusion criteria. The mean age of patients was 66.5 ± 11.5 years and 57.9% were male. Median follow-up was 623 (range 56-3841) days. A total of 62 recurrences occurred in 41 patients (13.8% of study population). Recurrences were managed with repeat transanal endoscopic surgery or endoscopic resection 67.7% and 25.8% of the time, respectively. Radical resection was required for adenocarcinoma in 4 patients. Recurrence-free survival rates were 93.4% at 1 year, 86.2% at 2 years, and 73.1% at 5 years. After adjusting for individual surgeons, adenoma height, size > 3 cm, high-grade dysplasia, positive margins, and management of the rectal defect, patients who underwent surgery in the latter 5 years of the study had lower odds of recurrence (OR 0.42, 95% CI 0.19, 0.93, p = 0.03).

[CONCLUSIONS] Rectal adenomas managed by transanal endoscopic surgery are lesions at high risk for recurrence; surveillance should be performed within the first 2 years and continued for a total of at least 5 years. Most recurrences can be successfully treated with repeat TEM or endoscopic resection.