Indications for performing transanal endoscopic microsurgery (TEM) in rectal cancer patients

Objective The aim of this study was to clarify the application of a local excision using TEM for rectal cancer. Patients and methods Fifteen patients were preoperatively diagnosed to have cancer invasion in the submucosa (T1) and thus were treated by TEM, while 13 others were preoperatively diagnosed to have cancer invasion reaching the muscularis propria (T2) and thus were treated by a radical operation. Surgical specimens from all 28 patients were pathologically examined and compared with the preoperative evaluation. Results The mean operating time for TEM was 53 min. The accuracy of the preoperative evaluation for the depth of cancer invasion was 68% (19/28). In the 15 patients with preoperative evaluation of T1 cancer, two pathologically showed cancer invasion into muscularis propria. In the 13 patients with a preoperative evaluation of T2 cancer, three pathologically showed cancer invasion within the submucosa. Conclusion Since some patients with a preoperative evaluation of T2 rectal cancer showed the possibility of a complete cure with a local excision, preoperative T2 stage rectal cancer is considered to be a good candidate for a local excision using TEM.