OBJECTIVETo explore the accuracy of endoscopic ultrasound (EUS) in preoperative staging of rectal cancer and to guide the treatment of transanal endoscopic microsurgery (TEM) in early rectal cancer.

METHODSClinical data of 80 patients with rectal cancer receiving EUS examination for preoperative staging in our department between June and December 2012 were retrospectively analyzed. Consistence comparison of EUS preoperative staging and pathological staging was performed to identify the accuracy of EUS preoperative staging. All the patients underwent operation within 1 week after EUS examination. According to preoperative staging, early rectal cancer(Tis or T1N0M0) patients with lesions less 20 cm to anus underwent TEM.

RESULTSThe overall accuracy of EUS for preoperative T stage was 68.8%(55/80), and for T1, T2, T3, T4 was 91.3%(73/80), 83.8%(68/80), 77.5%(62/80), 85.0%(67/80), which had a good consistence with postoperative pathological T staging(Kappa=0.562). The overall accuracy of EUS for preoperative N stage was 52.7%(39/74), and for N0, N1, N2 stage was 64.9%(48/74), 55.4%(41/74), 85.1%(63/74), which had a poor consistence with postoperative pathological N staging(Kappa=0.235). Six patients underwent TEM successfully, with mean operation time 99(65 to 123) min, without intraoperative and postoperative complication, and were discharged 2-3 days after operation. Enteroscope showed good recovery 1 month later. Pathology confirmed that all the lesions were early rectal cancer. During postoperative follow-up of 14.8 (11 to 19) months, there was no local recurrence and distant metastasis.

CONCLUSIONPreoperative EUS has a good accuracy with pathologic T stage, and can guide TEM in early rectal cancer.