Who should be followed up after transanal endoscopic resection of rectal tumours?

Objective To determine follow-up requirements following transanal endoscopic microsurgery (TEM) for rectal tumours based on clinical and histopathological assessment of resection specimens. Method A consecutive series of 117 patients undergoing TEM between 1997 and 2005 was studied. The excised specimens were classified as intact with clear surgical resection margins, macroscopically intact specimens with microscopically involved resection margins or piecemeal. Recurrence rates were determined for the three groups. Results Of the 117 procedures performed, 80 were for benign disease and 37 for malignancy. Within the benign group 39 (49%) resections were intact with clear surgical resection margins and yielded zero recurrences; 22 (27%) resections were macroscopically intact with microscopically involved surgical resection margin and yielded two recurrences; and 19 (24%) resections were piecemeal and yielded eight recurrences. Within the malignant group all 37 patients had resection specimens which were intact with clear surgical resection margins. Two patients had immediate salvage surgery. Of the 35 who went on to long-term follow-up post-TEM (0.6-8.1 years, median 4) four developed recurrent cancer (two local with submucosal disease and two liver metastases). Conclusion For benign rectal neoplasms, resection of an intact specimen with histologically clear surgical resection margins was associated with no observed mucosal recurrence. Local recurrence after TEM is significantly more frequent when histological examination reveals involved margins or when resection is piecemeal. Early endoscopic follow up is required for the latter two groups. Local recurrence for malignant cases was submucosal and detected by palpation.