Preoperative Imaging Staging of Rectal Cancer

Abstract

Carcinomas of the rectum are associated with a significant local and distant recurrence rate. Not all patients are appropriate candidates for preoperative radiation therapy. Preoperative identification of those most likely to benefit from neoadjuvant therapy is important. There is no general consensus on the role of endorectal ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) in staging patients with rectal cancer. Although the tumor stage is an important prognostic factor, preoperative assessment is associated with prediction of the circumferential resection margin. Newer developments such as coils, sequences and gradients in MRI, evolution of multidetector CT and new contrast media, allow for an algorithm selection aiming at the best diagnostic options for patients. The present review will discuss the current role of the various imaging modalities in staging carcinomas of the rectum.

MicroRNAs as Promising Biomarkers for Tumor-staging: Evaluation of MiR21 MiR155 MiR29a and MiR92a in Predicting Tumor Stage of Rectal Cancer

“…For rectal cancer in particular, over half of the metastatic nodes are less than 5 mm, which result in difficulty to evaluate lymph node involvement (Dworak, 1989;Mönig et al, 1999). There is a wide variation in accuracy for metastatic nodal detection with CT (22-73%) and MRI (39-75%) (Karantanas et al, 2007). However, in our study, miR155 seemed to have acceptable accuracy (85%) for predicting tumor N stage, which might potentially improve the diagnostic capability of imaging staging.…”

“…Biochemical tumor markers such as CEA and imaging examination like CT and MRI are used for early detecting and progression monitoring. However, due to their wide variation in accuracy, they are not the "golden standard" for RC preoperative diagnosis, even less so for tumor staging (Karantanas et al, 2007;Nishiumi et al, 2012). Therefore the search for novel markers indicating RC tumor stage is needed.…”

Rectal Carcinoma: Multi-Modality Approach in Curative Local Treatment of Early Rectal Carcinoma

“…ERUS is a well-tolerated procedure and usually does not require sedation. Carcinomas are hypoechoic, and the stage is determined by the scale to which they affect the rectal wall layers (Karantanas et al, 2007). The prefix "u" is used to represent stage and it corresponds to the TNM classification (Smith & Brown, 2008).…”

The value of FDG positron emission tomography/computerised tomography (PET/CT) in pre-operative staging of colorectal cancer: a systematic review and economic evaluation.

“…This technique is associated with a reduction in rates of recurrence and mortality. 60 Although successful surgical outcomes can increase life expectancy for some patients, secondary surgical resections often result in considerable morbidity and greatly diminished quality of life for survivors. 56 Accurate pre-operative re-staging is essential to distinguish those most likely to benefit from additional, sometimes drastic, surgery.…”

“…56 Accurate pre-operative re-staging is essential to distinguish those most likely to benefit from additional, sometimes drastic, surgery. 60 The procedures used in the routine follow-up of patients with a history of CRC vary but generally include blood testing to detect rising levels of carcinoembryonic antigen (CEA), imaging tests (predominantly CT) and clinical examination. 55,56 When recurrence is suspected, combinations of MRI, CT, chest radiography and ultrasound are used to confirm the presence or absence of disease and allow pre-operative staging to reclassify the disease status.…”