title: The prognostic value of tumour regression grade following neoadjuvant chemoradiation therapy for rectal cancer.
abstract: OBJECTIVE
  To date, there is no uniform consensus on whether tumour regression grade (TRG) is predictive of outcome in rectal cancer. Furthermore, the lack of standardization of TRG grading is a major source of variability in published studies. The aim of this study was to evaluate the prognostic impact of TRG in a cohort of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy (CRT). In addition to the Mandard TRG, we utilized four TRG systems modified from the Mandard TRG system and applied them to the cohort to assess which TRG system is most informative.
  
  
  METHODS
  One-hundred and fifty-three patients with a T3/T4 and/or a node-positive rectal cancer underwent neoadjuvant 5-fluorouracil-based CRT followed by surgical resection.
  
  
  RESULTS
  Thirty-six (23.5%) patients achieving complete pathological response (ypCR) had a 5-year disease-free survival (DFS) rate of 100% compared with a DFS rate of 74% for 117 (76.5%) patients without ypCR (P = 0.003). The Royal College of Pathologists (RCPath) TRG best condenses the Mandard five-point TRG by stratifying patients into three groups with distinct 5-year DFS rates of 100%, 86% and 67%, respectively (P = 0.001). In multivariate analysis, pathological nodal status and circumferential resection margin (CRM) status, but not TRG, remained significant predictors of DFS (P = 0.002, P = 0.035 and P = 0.310, respectively).
  
  
  CONCLUSIONS
  Our findings support the notion that ypCR status, nodal status after neoadjuvant CRT and CRM status, but not TRG, are predictors of long-term survival in patients with locally advanced rectal cancer.
authors.affiliation: Department of Medical Oncology, Beaumont Hospital, Our Lady of Lourdes Hospital, Drogheda and Royal College of Surgeons in Ireland, Dublin, Ireland; Department of Surgery, Our Lady of Lourdes Hospital, Drogheda and Royal, College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: K I
authors.initials: KI
authors.lastname: Abdul-Jalil
authors.forename: K M
authors.initials: KM
authors.lastname: Sheehan
authors.forename: J
authors.initials: J
authors.lastname: Kehoe
authors.forename: R
authors.initials: R
authors.lastname: Cummins
authors.forename: A
authors.initials: A
authors.lastname: O'Grady
authors.forename: D A
authors.initials: DA
authors.lastname: McNamara
authors.forename: J
authors.initials: J
authors.lastname: Deasy
authors.forename: O
authors.initials: O
authors.lastname: Breathnach
authors.forename: L
authors.initials: L
authors.lastname: Grogan
authors.forename: B D P
authors.initials: BD
authors.lastname: O'Neill
authors.forename: C
authors.initials: C
authors.lastname: Faul
authors.forename: I
authors.initials: I
authors.lastname: Parker
authors.forename: E W
authors.initials: EW
authors.lastname: Kay
authors.forename: B T
authors.initials: BT
authors.lastname: Hennessy
authors.forename: P
authors.initials: P
authors.lastname: Gillen
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy; D012074:Remission Induction; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil
keywords: Cancer; oncology; radiology