Additional value of MRI-detected EMVI scoring system in rectal cancer: applicability in predicting synchronous metastasis

Abstract

Introduction: Extramural vascular invasion (EMVI) has been recommended as an independent prognostic factor for poor overall survival rate in rectal cancer and can be used as a potential biomarker. Early prediction of prevalence of synchronous metastasis can elevate the disease-free survival rate. We aimed to evaluate the magnetic resonance imaging (MRI)–detected EMVI (mrEMVI) scoring system in predicting distant metastasis in T3 rectal cancer. Methods: Patients with postoperative histopathologically confirmed T3 rectal cancer without previous treatment from July 2014 to December 2015 were enrolled in this study. Two blinded radiologists evaluated mrEMVI status. mrEMVI was categorized as EMVI-positive or EMVI-negative in T2-weighted images using an mrEMVI scoring system. The results, along with other clinical characteristics (age, sex, tumor location, MRI-detected distance of mesorectal extension, lymphatic invasion, perineural invasion, mrEMVI score, and carcinoembryonic antigen [CEA]), were then correlated with synchronous metastases to determine the risk factors using univariate and multivariate analysis. Results: Of 180 patients, 38 were confirmed to be mrEMVI-positive, 142 mrEMVI-negative. There were 34 patients with synchronous metastasis, of whom 25 were mrEMVI-positive and 9 were mrEMVI-negative. Three factors were significantly associated with synchronous metastasis: mrEMVI ( p = 0.001; odds ratio = 8.665), histopathologic lymphatic invasion ( p = 0.001; odds ratio = 12.940), and preoperative CEA ( p = 0.026; odds ratio = 4.124). mrEMVI score 4 was more likely for synchronous metastasis ( p = 0.044; odds ratio = 9.429) than mrEMVI score 3 in rectal cancer. Conclusions: mrEMVI positivity is an independent risk factor for synchronous distant metastasis in rectal cancer. mrEMVI score 4 is a stronger risk factor for synchronous metastasis than mrEMVI score 3 in rectal cancer.

Risk Factors for Distant Metastasis in T3 T4 Rectal Cancer

“…Sohn et al 20 found that mrEMVI was a risk factor for distant metastasis of rectal cancer, and patients with mrEMVI-positive before treatment had a significantly higher risk of distant metastasis. Tripathi et al 21 found that mrEMVI-positive was an independent risk factor for synchronous distant metastasis of rectal cancer. In a recent meta-analysis, mrEMVI-positive patients had a five-fold increased incidence of synchronous metastases and an approximately 4-fold increased risk of postoperative metachronous metastases.…”

“… 28 - 30 Studies had shown that lymph node metastasis was associated with distant metastasis after colorectal cancer surgery, 28 , 29 and N stage was associated with the presence of synchronous distant metastasis in rectal cancer. 21 , 30 The assessment of lymph node metastasis mainly includes 2 aspects, the number and the location of lymph node metastases. It had been established that lymph node metastasis was an important independent prognostic factor for rectal cancer.…”

“…Many studies have shown that CEA levels (CEA ⩾ 5 ng/mL) are associated with synchronous or metachronous distant metastasis in rectal cancer. 21 , 30 , 34 The study of Restivo et al 35 showed that patients of advanced rectal cancer with high CEA levels had a higher risk of early distant metastasis. Wang et al 36 showed that high levels of CEA (> 10 ng/dL) may be associated with early metastases within 6 months after rectal cancer resection in patients treated with preoperative 30 Gy RT.…”

Extramural vascular invasion nomogram before radical resection of rectal cancer based on magnetic resonance imaging

“…For rectal cancer patients with EMVI status, the original low-signal vascular shadow on MRI is replaced by a moderate tumor signal (i.e., a continuous extension of the tumor signal in the vascular structure outside the intestinal wall), and the tumor signal leads to continuous or discontinuous vascular expansion ( 7 ). The Mercury research group has proposed a 5-point MRI scoring system to evaluate EMVI in rectal cancer: 0: the mass penetrates the rectum wall but is smooth externally with no adjacent vessels, and MRI evaluation; 1: the mass extends in strips through the rectum wall, no adjacent vessels; 2: the mass extends in strips through the rectum wall, adjacent blood vessels, but no tumor-like signal was found in the vascular lumen, MRI evaluation; 3: the mass extends in strips through the rectum wall, adjacent blood vessels showed moderate tumor-like signal in the lumen, lumen widening, and MRI evaluation; 4: a moderate tumor-like signal in the lumen of the adjacent large vessels (above/middle/lower rectal veins) with an irregular vascular outline, MRI evaluation ( 8 ). A 5-grade scoring system using MRI to predict EMVI was created.…”

Risk of nodal disease in patients with MRI-detected extramural vascular invasion in rectal cancer: a systematic review and meta-analysis

“…2,[6][7][8] Magnetic resonance imaging-detected extramural vascular invasion (mrEMVI), which can independently predict local and distant metastasis, is an important prognostic factor. [9][10][11][12][13][14][15][16][17][18] It has been shown to correlate with relapse-free survival and overall survival. 9,12,13,19 The majority of recent studies concerning mrEMVI status focused only on disease-free survival (DFS), overall survival (OS), posttreatment effects, and magnetic resonance imaging (MRI) diagnosis accuracy.…”