Endoscopy 2011; 43 - A31
DOI: 10.1055/s-0031-1292102

EUS and Magnetic Resonance Image (MRI) in the staging of rectal cancer. A prospective and comparative study

A Ginès 1, G Fernández-Esparrach 1, JR Ayuso-Colella 2, O Sendino 1, C Ayuso-Colella 2, M Pagés 2, M Cuatrecasas 3, L Jáuregui 1, M Pellisé 1, J Maurel 4, JM Bordas 1, J Llach 1, A Castells 1
  • 1Endoscopy Unit. Hospital Clínic. IDIBAPS. CIBERehd. Barcelona. Spain
  • 2Radiology Department
  • 3Pathology Department
  • 4Oncology Department. Hospital Clínic. Barcelona. Spain

Background: Accurate locorregional staging is crucial in rectal cancer for deciding patients' management, since the administration of neoadjuvant therapy depends on it. EUS and MR are used in the pretherapeutic work-up of rectal cancer. However, both techniques have not been prospectively compared in a large series of patients.

Aim: To prospectively compare the performance characteristics of EUS and MR in the locoregional staging of rectal cancer in a large series of patients.

Methods: Inclusion criteria were: histologically proved rectal cancer and written informed consent. Patients included underwent both, EUS and MR. Epidemiological, clinical, radiological and echographic variables were evaluated. Gold standard used was de pathological examination of the surgical specimen.

Results: Between January 2007 and July 2009, 220 patients with rectal cancer were included. EUS and RM could not be performed in 22 (10%) and 16 (7%) of patients respectively for different reasons, but only in 5 patients (2%) there was a formal contraindication for MR (pacemarker or claustrophobia). Nine patients were lost before starting any treatment; therefore, 166 patients with pre-operative EUS and RM were treated. Of them, 65 (39%) were operated and constitute the study polulation. The remaining 101 were treated with neoadjuvant therapy (n=83, 38%) or palliative techniques (n=18, 11%).

Of the 65 patients operated, genders were 24F/37M, with a mean age of 69+37 (range 33–87). The mean distance of the tumor to the anus was 9.2+4 cms (range 2–15). Most of the tumors (64%) were at stages T2-T3. Seven (11%) tumors were stenotic and 22 (35%) had polypoid morphology. The accuracy of EUS and MR in T and N staging was 60% and 75% (T staging) and 50% and 69% (N staging) respectively (p=ns). There were no statistically significant differences between both techniques in sensitivity, specificity, PPV and NPV.

The univariate analysis showed that the presence of stenosis and the polypoid morphology of the tumor inversely correlate with accuracy in both, EUS and MR.

Conclusions: EUS and RM have similar accuracy in the T and N staging in rectal cancer. The presence of a stenosis and a polypoid morphology are inversely associated with accuracy either for EUS or RM.