title: Extramural venous invasion is a potential imaging predictive biomarker of neoadjuvant treatment in rectal cancer.
abstract: BACKGROUND
  Extramural venous invasion (EMVI) is a poor prognostic factor in rectal cancer and identified on magnetic resonance imaging (MRI) (mrEMVI). The clinical relevance of improvement in mrEMVI following neoadjuvant therapy is unknown. This study aimed to demonstrate that regression of mrEMVI following neoadjuvant chemoradiotherapy (CRT) results in improved outcomes and mrEMVI can be used as an imaging biomarker.
  
  
  METHODS
  Retrospective analysis of prospectively collected data was conducted examining the staging and post-treatment MRIs of patients who had presented with EMVI-positive rectal cancer. All patients had undergone neoadjuvant CRT and curative surgery. Changes in mrEMVI were graded with a new MRI-based TRG scale-mr-vTRG; and related to disease-free survival (DFS). The study fulfilled Reporting Recommendations for Tumour Marker Prognostic Studies criteria for biomarkers.
  
  
  RESULTS
  Sixty-two patients were included. Thirty-five patients showed more than 50% fibrosis of mrEMVI (mr-vTRG 1-3); 3-year DFS 87.8% and 9% recurrence. Twenty-seven patients showed less than 50% fibrosis (mr-vTRG 4-5); 3-year DFS 45.8% with 44% recurrence - P<0.0001. On multivariate Cox-regression, only mr-vTRG 4-5 increased risk of disease recurrence - HR=5.748.
  
  
  CONCLUSIONS
  Patients in whom there has been a significant response of EMVI to CRT show improved DFS. Those patients with poor response should be considered for intensive treatment. As an imaging biomarker in rectal cancer, mrEMVI can be used.
authors.affiliation: 1] Department of GI Radiology, Royal Marsden Hospital, Downs Road, Sutton, SM2 5PT, UK [2] Department of Surgery and Cancer, Imperial College, London, UK [3] Department of Surgery, Croydon University Hospital, London Road, Croydon CR7 7YE, UK.
authors.forename: M
authors.initials: M
authors.lastname: Chand
authors.affiliation: Department of Surgery, Croydon University Hospital, London Road, Croydon CR7 7YE, UK.
authors.forename: R I
authors.initials: RI
authors.lastname: Swift
authors.affiliation: 1] Department of GI Radiology, Royal Marsden Hospital, Downs Road, Sutton, SM2 5PT, UK [2] Department of Surgery and Cancer, Imperial College, London, UK.
authors.forename: P P
authors.initials: PP
authors.lastname: Tekkis
authors.affiliation: Department of GI Radiology, Royal Marsden Hospital, Downs Road, Sutton, SM2 5PT, UK.
authors.forename: I
authors.initials: I
authors.lastname: Chau
authors.affiliation: 1] Department of GI Radiology, Royal Marsden Hospital, Downs Road, Sutton, SM2 5PT, UK [2] Department of Surgery and Cancer, Imperial College, London, UK.
authors.forename: G
authors.initials: G
authors.lastname: Brown
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012004:Rectal Neoplasms / Q000098:blood supply* / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor