Does EUS Truly Make a Clinical Impact On the Management of Rectal Cancer? A Prospective, Blinded, Single Center Study

Abstract

Background: EUS and CT have been used for staging of rectal cancer. Accurate pre-op assessment allows for an optimal treatment plan, as neoadjuvant therapy is administered to those individuals with T3, T4, or nodal disease. This prospective study analyzes the utility of EUS as an adjunct to digital rectal exam (DRE), endoscopic appearance of the tumor, and CT for the management of patients with newly diagnosed rectal cancer. Method:23 patients (14 male, mean age 58 ± 14 yo) with newly diagnosed rectal cancer between July 2005 and July 2006 prospectively underwent DRE, sigmoidoscopy, CT, and EUS. One of two colorectal surgeons (EF and CF) performed a DRE and endoscopically viewed the tumor. They were then asked to make a management decision based on their DRE, endoscopic appearance of the tumor, and CT results to recommend resection, neoadjuvant therapy followed by resection, or palliation. DRE and EUS were then performed by a dedicated GI ultrasonographer (VMS) blinded to the surgeons findings. Treatment decisions of the colorectal surgeons using this additional information in a blinded fashion was then compared to determine if EUS altered clinical management. Coefficients of agreement (K) were calculated between reader's treatment decisions. Results: In two patients the gastroenterologist could not reach the tumor by DRE. Of the cases where both the colorectal surgeon and the gastroenterologist performed a DRE there was near complete correlation (K = .872, 95% CI 0.76-0.95). A moderate amount of correlation was found between the surgeons DRE and the endoscopic ultrasound (K = .642, 95% CI 0.76-0.95). The EUS changed the treatment plan on 3/23 (13%) of patients. The colorectal surgeons overstaged 2 patients who they felt had T3 tumors and would benefit from neoadjuvant therapy. EUS found both of the overstaged patients to have T2 disease which was confirmed by surgical pathology. One patient was understaged by DRE (as compared to EUS) however, because the patient underwent neodjuvant therapy, surgical pathology is not available. Conclusion: This study shows that the addition of EUS to DRE, endoscopic appearance of the tumor, and CT offers modest additional information to the initial stratification of patients with rectal cancer in the hands of expert colorectal surgeons. However, in patients where the tumor is too proximal to feel by DRE, EUS may add important information to guide management in patients with newly diagnosed rectal cancer. Further larger scale studies are needed to confirm this data.