This document summarizes several studies on transanal total mesorectal excision (TaTME) surgery: - Studies from 2010-2009 evaluated TaTME techniques with small patient numbers, including laparoscopic disc and lone star retractor approaches. - Leroy 2013 and Colombo 2015 compared TaTME to robotic surgery. - COLOR I and II were large, matched control studies comparing laparoscopic to open colon and rectal cancer surgery, finding short-term benefits to laparoscopic. - COLOR III is an ongoing study directly comparing laparoscopic TME to TaTME.