Application of endoscopic sonography in preoperative staging of rectal cancer: six-year experience.

Objectives-The aim of this study was to evaluate our experience with the application of endoscopic sonography in preoperative staging of rectal cancer. Methods-Between April 2004 and May 2010, 192 patients with rectal cancer first underwent endoscopic sonography and then underwent surgery at our hospital. None of the patients in this study received neoadjuvant therapy. The endoscopic sonographic staging results were compared with those of postoperative pathologic staging. Results-The accuracy of overall T staging was 86.5%, and for Ti, T2, T3, and T4, the accuracy rates were 86.7%, 94.0%, 86.2%, and 65.5%, respectively. The accuracy of T staging for ulcerated lesions was significantly lower than that for nonulcerated lesions (P=.013). The accuracy of T staging between nontraversable stenotic lesions and traversable lesions was also significantly different (P=.002). The accuracy of N staging was 77.8%, and the specificity and sensitivity were 85.6% and 74.2%, respectively. Conclusions-Endoscopic sonography is safe and effective for preoperative staging of rectal cancer and should be a routine examination before surgery. As for ulcerated and nontraversable stenotic lesions, however, the results of endoscopic sonographic staging could be doubtful. Moreover, the accuracy of endoscopic sonographic N staging still needs modification by further research.