title: MRI-detected extramural vascular invasion is an independent prognostic factor for synchronous metastasis in patients with rectal cancer.
abstract: OBJECTIVE
  To determine whether magnetic resonance imaging (MRI)-detected extramural vascular invasion (EMVI) could predict synchronous distant metastases in rectal cancer.
  
  
  METHODS
  Patients who underwent rectal MRI between July 2011 and December 2012 were screened. This study included 447 patients with pathologically confirmed rectal adenocarcinoma who had undergone MRI without previous treatment. Distant metastases were recorded at the initial work-up and over a 6-month follow-up. Univariate/multivariate logistic regression models were used to determine the risk of metastasis. The diagnostic performance was calculated using pathologic lymphovascular invasion (LVI) as a gold standard.
  
  
  RESULTS
  Among 447 patients, 79 patients (17.7 %) were confirmed to have distant metastases. Three MRI features are significantly associated with a high risk of distant metastasis: positive EMVI (odds ratio 3.02), high T stage (odds ratio 2.10) and positive regional lymph node metastasis (odds ratio 6.01). EMVI in a large vessel (≥3 mm) had a higher risk for metastasis than EMVI in a small vessel (<3 mm). Sensitivity, specificity and accuracy of MRI-detected EMVI were 28.2 %, 94.0 % and 80.3 %, respectively.
  
  
  CONCLUSIONS
  MRI-detected EMVI is an independent risk factor for synchronous metastasis in rectal cancer. EMVI in large vessels is a stronger risk factor for distant metastasis than EMVI in small vessels.
  
  
  CONCLUSIONS
  • EMVI, LN metastasis and T staging on MRI are risk factors for metastasis. • EMVI in large vessels has greater risk for metastasis than in small vessels. • Regional LN metastasis on MRI has highest risk for predicting metastasis. • MR findings could be helpful for selecting patients at high risk for metastasis.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University, College of Medicine, 250 Seongsanno (134 Sinchon-dong), Seodaemun-gu, Seoul, Korea, 120-752.
authors.forename: Beomseok
authors.initials: B
authors.lastname: Sohn
authors.forename: Joon-Seok
authors.initials: JS
authors.lastname: Lim
authors.forename: Honsoul
authors.initials: H
authors.lastname: Kim
authors.forename: Sungmin
authors.initials: S
authors.lastname: Myoung
authors.forename: Junjeong
authors.initials: J
authors.lastname: Choi
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000473:pathology*; D012004:Rectal Neoplasms / Q000473:pathology*; D012007:Rectum / Q000098:blood supply* / Q000473:pathology*; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity