Colon Cancer Staging: When Does High Resolution MRI Have a Role?

Abstract

Contrarily to what happens with rectal cancer, the role of magnetic resonance imaging (MRI) in the assessment of colon cancer has been limited. However, we may witness a ‘paradigm shift’ in the future. Classically, colon cancer has been assessed by computed tomography (CT) which is considered the workhorse for evaluating this neoplasm as it provides insights not only about local and regional disease as well as about distant metastases. However, as the accuracy of CT is somewhat limited, recent reports about the use of MRI in colon cancers have been published. In this review we will assess the potential role of MRI in the setting of colon cancer, with particular emphasis on primary staging. Overall, MRI seems to offer the potential to distinguish between locally advanced and not locally advanced colon cancers. High resolution MRI may have an advantage in comparison to other techniques – namely CT – related to its high soft tissue discrimination. MRI can, in most studies, identify prognostic factors such as T-stage and extramural venous invasion. However, nodal characterization by MRI has some drawbacks that have a negative impact on the accuracy of the technique. Current evidence about the role of MRI in colon cancer staging is still limited. Although the works published so far offer promising results, the role of this imaging modality is largely dependent on the possible implementation of neoadjuvant chemotherapy for locally advanced colon cancers. In this setting, MRI may be very helpful in selecting patients who can benefit from that therapy. Further research on the field, including large multi-institutional studies, is warranted.