Fig. 1

Patient selection of this study: patients with mid and low rectal cancer with lesions ≤8 cm away from the anal verge were included. Patients who were administered long-term (more than 30 days) neoadjuvant chemoradiotherapy or received radical resection after waiting for more than 30 days after receiving short-term (5 days) radiotherapy were excluded from this study due to the possibility of tumor regression. Other histologic types other than adenocarcinoma were listed and excluded. Patients who received subtotal colectomy due to familial polyposis, local excision including four who underwent transrectal polypectomies, 39 who had transanal excisions, and 15 who underwent transanal endoscopic microsurgeries were excluded. In the last step, we moved the patients who had positive N stage to supplement information