Transrectal Ultrasound (TRUS) Helps Select Patients for Transanal Excision (TAE) of Early (T1) Rectal Cancers and Large Polyps

Abstract

Transrectal Ultrasound (TRUS) Helps Select Patients for Transanal Excision (TAE) of Early (T1) Rectal Cancers and Large Polyps Girish Mishra, Saulette Roberson, John Sweeney, Edward Levine, Russell Howerton, Greg Waters Background and Significance: TAE is an extremely effective and attractive surgical approach in patients with T1 rectal cancers and polyps that are not amenable to endoscopic removal. T2 rectal cancers have a higher local recurrence rate and may be selected for more invasive surgery with either a low anterior resection,or an abdomino perineal resection. Thus, accurate staging is critical in selecting patients for a TAE. TRUS is highly sensitive in T and N-staging for rectal cancer, but its diagnostic accuracy for distinguishing T1 and T2 rectal cancers has been challenged. Study Aims: To determine the accuracy of TRUS in determining resectability by TAE for T1 rectal cancers and polyps too large to be resected endoscopically. Methods: 183 TRUS were performed at our institution between August 2001 and October 2004. 21 TAE were performed for either T1 lesions by TRUS or for large polypoid masses localized to the mucosa by TRUS, but technically challenging to remove endoscopically. Results: The mean age of patients staged either T1 or T2 was 62 (33-80). 13 of 15 patients (87%) were accurately classified as having T1 disease. 2 lesions were understaged. 6 polypoid lesions (100%) that were either tubulovillous or villous adenomas were accurately classified as being localized to the mucosa. All patients (nZ11) staged T2 by TRUS were confirmed to be T2 at pathology. No difference was noted in the predictive value of TRUS for T1 vs T2 lesions (pZ.4923, exact test). Correlation between TRUS and pathology was kZ.85.Conclusions: TRUS is highly accurate in delineating depth of invasion for T1 rectal cancers and large, polypoid lesions unamenable to polypectomy. The ability to accurately delineate T1 vs T2 rectal cancer by TRUS allows for the appropriate selection of patients for TAE and thus, avoidance of more invasive surgery with higher morbidity and mortality. Abstracts