Pre-operative staging of recto-sigmoid colon carcinoma by upper gastrointestinal endoscopic ultrasonography.

BACKGROUND/AIMS: To assess the accuracy of a new generation endoscopic ultrasonography (EUS)(GF-M200) in pre-operative staging of recto-sigmoid colon carcinoma invasion and lymph node metastasis.

METHODOLOGY: Seventy-three patients with biopsy proven colon cancer were included in this study. These comprised 60 patients with rectal carcinoma and 13 patients with sigmoid carcinoma. All patients were pre-operatively examined by EUS. Pathological findings of the depth of tumor invasion and presence of lymph node metastasis were correlated with EUS.

RESULTS

EUS has an overall accuracy rate of 89% in staging of recto-sigmoid cancer. The diagnostic accuracy rate was 83% for T1, 83% for T2, 93% for T3, and 71% for T4. Understaging and overstaging occurred in 6% and 6%, respectively. In determining lymph node metastasis, the overall accuracy rate was 77%, with a sensitivity and specificity rate of 77% and 76%, respectively.

CONCLUSIONS

EUS is a valuable staging modality in the staging of the depth of tumor invasion, not only for rectal carcinoma but also for tumors located at the sigmoid colon.