Preoperative staging using transrectal ultrasound in high and low rectal cancer

Background: An accurate preoperative definition of tumor and lymph node status is needed for reaching the correct decision regarding rectal cancer treatment. Transrectal ultrasonography is the most commonly used diagnostic modality for the local staging of rectal cancer. Objectives: To determine the accuracy of TRUS in the staging of rectal cancer. Methods: We conducted a retrospective study on 95 patients evaluated by TRUS. The rectum was subdivided into two parts (lower and upper). Results: Sixty patients underwent radical surgery. Of these, 34 received no preoperative chemo-irradiation owing to lT1, T2 tumor or the patient's choice (neo-adjuvant treatment was suggested to patients with adenocarcinoma that proved to be T3). The overall accuracy rate was 80% for T stage. Overstaging was found in 13.3% and understaging in 6.7%.The N-stage was correctly assessed in 70%. The overall accuracy rate for tumors was 73.9% in the lower part and 90.9% in the upper. A trend towards a lower accuracy rate for low-lying tumors compared to high-located rectal tumors was found (P = 0.532), which did not reach statistical significance. Conclusions: TRUS gave better results for T1 and T3 stage rectal tumors but was inaccurate for stage T2, indicating the possible need for local excision in order to base the final treatment for T2 tumors on pathologic staging.