Local recurrence after transanal endoscopic microsurgery for rectal polyps and early cancers.

Background: Transanal endoscopic microsurgery (TEM) allows for local excision of rectal neoplasms with greater exposure than transanal excision and less morbidity than transabdominal approaches. This study examines the implications of the procedure with respect to predictors of recurrence.

Methods: We performed a retrospective analysis of 144 consecutive TEMs from 1993 to 2004.

Results: The study comprises 107 patients presenting for TEM with benign disease and 32 patients with cancer. Patients had a mean age of 64+/-14 (SD) years. TEM was performed for recurrent lesions in 17% of cases. Pathologic classification of the lesions after TEM was benign adenoma in 45%, adenoma with high-grade dysplasia (HGD) in 17%, cancer in 33%, and other in 4%. Complications occurred in 10%, and local recurrence occurred in 15% of patients. Median follow-up was 44 months, with a median time to recurrence of 14 months. Positive margins did not influence lesion recurrence. Recurrence of cancers correlated with the depth of tumor invasion (P<.05). On multivariate analysis, independent predictors of recurrence were lesion size and the presence of HGD within adenomas (P<.05). Five-year neoplastic recurrence probabilities were 11% for benign adenomas, 35% for adenomas with HGD, and 20% for cancers (P=.31); invasive recurrence probabilities were 0% for benign adenomas, 15% for adenomas with HGD, and 13% for cancers (P<.05).

Conclusions: Close endoscopic follow-up is warranted after TEM for both benign and malignant disease, with special attention to lesions with HGD. TEM can be performed safely for early rectal cancer with careful patient selection.