Clinical value of MRI‐detected extramural venous invasion in rectal cancer

Abstract

Extramural venous invasion (EMVI) is associated with a poor prognosis and a poor overall survival rate in rectal cancer. It can independently predict local and distant tumor recurrences. Preoperative EMVI detection in rectal cancer is useful for determining the treatment strategy. EMVI status is beneficial for the post-treatment evaluation and analysis of rectal cancer. Magnetic resonance imaging (MRI) is a non-invasive diagnostic modality with no radiation effects. High-resolution MRI can detect EMVI with high accuracy. In addition, MRI results are equal to or even better than pathological results in the detection of medium to large EMVI in rectal cancer. MRI-detected EMVI (mrEMVI) can be used as a potential biomarker that facilitates treatment methods. This review highlights the importance of MRI before and after rectal cancer treatment. In addition, we analyze the prognostic correlation between mrEMVI and circulating tumor cells (CTC) in rectal cancer. This article may help shed light on the significance of mrEMVI.

Magnetic resonance imaging for clinical management of rectal cancer: Updated recommendations from the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting

“…In 2012, reporting of EMVI after CRT was not advised unanimously. This change is likely the result of emerging evidence supporting EMVI as an important prognostic staging factor [ 25 – 27 ].…”

Predictive value of MRI-detected extramural vascular invasion in stage T3 rectal cancer patients before neoadjuvant chemoradiation

“…Circulating tumor cells (CTCs) originate from the primary tumor and vessel surrounding the tumor, which is one of the main routes of metastasis. CTCs are not only used as a prognostic factor, but also as a predictive biomarker in colorectal cancer and there exists a directly proportional relationship with EMVI (17). In addition, correlations were found between mr-EMVI scores and vascular endothelial growth factor (VEGF) expression in T3 rectal cancers (18).…”

Watch and wait approach in rectal cancer: Current controversies and future directions

“…Some authors have suggested that the quantitative evaluation of the apparent diffusion coefficient (ADC) could be beneficial; however, the results to date have been variable and-given the overlap between benign and malignant ADC values and the complex extrapolation between MRI scanners - no clear recommendations can be made at present[ 16 , 46 - 48 ]. Although ADC has other potential uses (primary staging, assessment of nodal disease and extramural vascular infiltration) the current evidence base is insufficient to draw any definitive conclusions; that said, some authors have suggested that ADC may be useful in certain well-defined cases[ 16 , 49 , 50 ].…”