Is endorectal ultrasound still useful for staging rectal cancer?

Staging in rectal carcinoma is important for planning treatment. Preoperative staging and treatment strategies have changed along with improvements in imaging techniques. The aim of this work is to evaluate the accuracy of endorectal ultrasound (ERUS) in rectal cancers, especially in low rectal cancers and stenotic cases.

From January 2011 to December 2011, patients diagnosed with rectal cancer who were admitted to our endosonography unit for staging and who were operated on in our hospital were evaluated retrospectively. Patients who received neoadjuvant chemotherapy were excluded. Endosonographic staging was compared to postoperative pathological staging.

In total, 38 patients (28 males, 10 females) were included. Their mean age was 57.6±11.3 years (27-75 years). Thirteen (34.2%) had stenotic lesions. The accuracy of ERUS for staging of lesions was evaluated according to pathology and was 73.7% overall (kappa coefficient = 0.317; p = 0.002). When patients were split into stenotic and non stenotic groups, the accuracy was 68% (kappa coefficient = 0.170; p = 0.125) for stenotic lesions and 84.6% (kappa coefficient = 0.606; p = 0.001) for non-stenotic lesions. Internal and external sphincter involvement were significantly correlated with the postoperative pathological evaluation in both groups.

Technological improvements in imaging methods have made the diagnosis and management of malignancies more precise. Low rectal tumours, have difficult characteristics for evaluation because of their unique location. Although ERUS has some disadvantages, it is still useful for T staging, evaluating sphincter involvement, and defining tumour size and distance from the anal verge. ERUS was less accurate for T staging of stenotic tumours, but the accuracy may still be within acceptable limits.