The Prognostic Significance of Postchemoradiotherapy High-resolution MRI and Histopathology Detected Extramural Venous Invasion in Rectal Cancer

Abstract

Detection of EMVI post-CRT is prognostically significant whether detected by MRI or histopathology. EMVI status after treatment may be used to counsel patients regarding ongoing risks of metastatic disease, implications for surveillance, and systemic chemotherapy.

A meta-analysis comparing the risk of metastases in patients with rectal cancer and MRI-detected extramural vascular invasion (mrEMVI) vs mrEMVI-negative cases

“…Six articles (Smith et al , 2008; Hunter et al , 2012; Bugg et al , 2014; Sohn et al , 2014; Seehaus et al , 2015; Chand et al , 2015) reporting on metastatic disease in patients with rectal cancer and EMVI that were retrieved from the electronic databases met the inclusion criteria (Supplementary Table 1). Two studies were from the same centre but evaluated different time cohorts (Smith et al , 2008; Chand et al , 2015).…”

“…Two studies were from the same centre but evaluated different time cohorts (Smith et al , 2008; Chand et al , 2015). One study included a combination of synchronous and metachronous metastases (predominately synchronous), and was included in the analyses for both outcome measures; exclusion of this study did not alter the significance for both synchronous or metachronous metastases (Sohn et al , 2014).…”

“…This led to the standardisation of MRI-detected extramural vascular invasion (mrEMVI) definitions in the preoperative assessment of rectal cancer as ‘serpiginous extension of tumour signal within a vascular structure – resulting in contiguous or discontinuous expansion of a vein by tumour signal’ (Supplementary Figure 1; Brown et al , 2003; Taylor et al , 2008, 2014a; Smith et al , 2008; Shihab et al , 2011; Nougaret et al , 2013; Chand et al , 2014b). By comparing pre and post-treatment scans, magnetic resonance imaging (MRI) identifies the persistence of EMVI in a greater percentage of patients than histopathology (mrEMVI; Chand et al , 2015) and has a high sensitivity even when enhanced histopathological techniques are used (Jhaveri et al , 2016). Several studies have reported the prevalence of mrEMVI and its correlation to the development of metastatic disease (Smith et al , 2008; Hunter et al , 2012; Bugg et al , 2014; Sohn et al , 2014; Seehaus et al , 2015; Chand et al , 2015; Kim et al , 2016).…”

“…By comparing pre and post-treatment scans, magnetic resonance imaging (MRI) identifies the persistence of EMVI in a greater percentage of patients than histopathology (mrEMVI; Chand et al , 2015) and has a high sensitivity even when enhanced histopathological techniques are used (Jhaveri et al , 2016). Several studies have reported the prevalence of mrEMVI and its correlation to the development of metastatic disease (Smith et al , 2008; Hunter et al , 2012; Bugg et al , 2014; Sohn et al , 2014; Seehaus et al , 2015; Chand et al , 2015; Kim et al , 2016). Given the standardised, reproducible and prognostically validated methods of describing tumour using MRI, it is considered a standard for preoperative risk stratification and treatment decision-making (Brown et al , 2003; Ernst-Stecken et al , 2004; Mercury Study Group, 2006; Smith et al , 2008; NICE, 2011; Shihab et al , 2011; Taylor et al , 2011, 2014b; Glimelius et al , 2013; Yu et al , 2014; Battersby et al , 2016; National Comprehensive Cancer Network 2015; Chand et al , 2015).…”

Imaging biomarker roadmap for cancer studies

“…Typically, prospective testing of IBs in clinical populations is required in adequately powered studies with follow-up times of 3–5 years to provide outcome data associated with the IB. For example, in patients with colorectal cancer, parameters such as circumferential resection margin56, depth of tumour spread, and extramural vascular invasion90, are assessed by MRI before surgery, have been validated as preoperative prognostic and predictive IBs, and are currently used to stratify patients into treatment groups. Similarly, ongoing work is evaluating the role of tumour CT, MRI and PET ‘radiomic signatures’ (REF.…”