title: Neoadjuvant chemoradiotherapy for rectal cancer: how important is tumour regression?
abstract: BACKGROUND
  Pathological complete response following neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer is associated with reduced local recurrence and improved long-term outcome. However, the prognostic value of a partial response, or of tumour regression in patients with metastatic disease, is less clear.
  
  
  METHODS
  We present a single-centre cohort study of 205 patients with stage II-IV rectal cancer treated with surgery and neoadjuvant CRT between 2006 and 2013. Tumour regression was assessed using the Dworak system.
  
  
  RESULTS
  The probability of 3-year recurrence-free survival (RFS) was 95% for Dworak grade 4, 82% for grade 3, 64% for grade 2 and 53% for grade 1 (P = 0.0005). In univariate regression analysis, Dworak grade was associated with RFS (hazard ratio (HR) 0.51, P < 0.0001; trend analysis) and cancer-specific survival (HR 0.52, P = 0.002). In multivariate analysis, Dworak grade remained an independent predictor of RFS (HR 0.62, P = 0.012), along with clinical metastases stage, resection margin status, the presence or absence of extramural venous invasion and type of surgical procedure.
  
  
  CONCLUSIONS
  Tumour regression grade after neoadjuvant CRT was an independent prognostic factor for RFS, highlighting the importance of the degree of local response to CRT.
authors.affiliation: Colorectal Cancer Research Group, St John of God Subiaco Hospital, Perth, Western Australia, Australia.|School of Medicine and Pharmacology, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Melanie J
authors.identifier: http://orcid.org/0000-0002-7402-2718
authors.initials: MJ
authors.lastname: McCoy
authors.affiliation: Division of Anatomic Pathology, St John of God Pathology, Perth, Western Australia, Australia.|School of Surgery, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: Hemmings
authors.affiliation: Division of Anatomic Pathology, St John of God Pathology, Perth, Western Australia, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Hillery
authors.affiliation: Colorectal Cancer Research Group, St John of God Subiaco Hospital, Perth, Western Australia, Australia.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Penter
authors.affiliation: Institute for Health Research, University of Notre Dame Australia, Fremantle, Western Australia, Australia.
authors.forename: Max K
authors.initials: MK
authors.lastname: Bulsara
authors.affiliation: Colorectal Cancer Research Group, St John of God Subiaco Hospital, Perth, Western Australia, Australia.|School of Surgery, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Nik
authors.initials: N
authors.lastname: Zeps
authors.affiliation: Colorectal Cancer Research Group, St John of God Subiaco Hospital, Perth, Western Australia, Australia.|School of Surgery, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Cameron F
authors.initials: CF
authors.lastname: Platell
mesh_terms: D000359:Aftercare; D000368:Aged; D059248:Chemoradiotherapy / Q000379:methods*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging*; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: chemoradiotherapy; neoadjuvant therapy; prognosis; rectal neoplasms; treatment outcome