Last update:
11-Nov-2004

OBJECTIVE The contribution of endoscopic ultrasonography (EUS) in the preoperative diagnosis and staging of colorectal carcinoma is assessed in this study.

METHOD The study included 80 patients (47 males and 33 females) with colorectal cancer. The regional topography of the disease was as follows: 30 patients had rectal cancer, 26 patients had cancer of the sigmoid colon, 6 of the descending colon, 2 in the transverse colon, 6 in the ascending colon and 10 had malignancy of the cecum. Preoperatively all 80 patients underwent complete clinical and laboratory investigation, radiological check, colonoscopy with biopsies, abdominal ultrasound, abdominal computerized tomography scan and EUS. EUS was performed by an Olympus Company modality (CF/UM3), consisting of a front view endoscope and basic ultrasound equipment. The ultrasonid transducer was incorporated into the tip of the endoscope and operated at a frequency of 7.5 MHz. The 5 layers of the colorectal wall, the origin of the disease and the extent of infiltration into the wall and the adjacent structures, organs and lymph nodes are precisely depicted on EUS and lead to cancer staging. These findings were compared with the results of the histological examination of colorectal biopsy and surgical specimens.

RESULTS The T staging sensitivity of EUS compared with the histological results was 93.8% and the specificity was 99.2%. The N staging sensitivity of EUS compared with the histological results was 93.8% and the specificity was 97.9%.

CONCLUSIONS The contribution of EUS in the preoperative diagnosis and local staging of colorectal carcinoma plays a significant role in the therapeutic management of the disease. EUS in comparison with the other established diagnostic and imaging techniques is the most accurate method for the staging of colorectal cancer.

Key words: Colorectal cancer, Endoscopic ultrasonography, Staging.