[The preoperative staging of rectal neoplasms: the clinical exam and diagnostic imaging]

Abstract

The management of rectal cancer remains an important clinical problem. Although there was been great progress in surgical management, the survival of patients with locally advanced disease has not improved significantly during the past decades. Preoperative staging and evaluation of the risk of recurrence may help in the choice of operation. It is difficult for clinicians to quantify reliably with digital examination the degree of fixation of the tumor, and they usually cannot distinguish nodal metastases except in advanced cases. The more frequent overstaging of small tumors within one quadrant of the rectum is a major drawback of digital examination. Computed tomography and magnetic resonance seems to underestimate the extension of rectal tumors, but both can be helpful in selecting patients with advanced tumors for whom preoperative adjuvant treatment is being considered. Endoluminal ultrasound is superior in staging tumors confined to the rectal wall, but is not the ideal tool for staging: the results are examiner dependent, the field of vision in depth is limited, and stricturing tumors cannot be passed by the ultrasound transducer. Imaging diagnostic attendibility confirms the preeminent role of intraoperative exploration in the assessment of neoplastic diffusion in order to plan a correct surgical treatment.