title: Predictive factors of tumor response after neoadjuvant chemoradiation for locally advanced rectal cancer.
abstract: OBJECTIVE
  Neoadjuvant chemoradiation followed by surgery is the standard of care for locally advanced rectal cancer. The aim of this study was to correlate tumor response to survival and to identify predictive factors for tumor response after chemoradiation.
  
  
  METHODS
  From 1998 to 2008, 168 patients with histologically proven locally advanced adenocarcinoma treated by preoperative chemoradiation before total mesorectal excision were retrospectively studied. They received a radiation dose of 45 Gy with a concomitant 5-fluorouracil (5-FU)-based chemotherapy. Analysis of tumor response was based on lowering of the T stage between pretreatment endorectal ultrasound and pathologic specimens. Overall and progression-free survival rates were correlated with tumor response. Tumor response was analyzed with predictive factors.
  
  
  RESULTS
  The median follow-up was 34 months. Five-year disease-free survival and overall survival rates were, of 44.4% and 74.5% in the whole population, 83.4% and 83.4%, respectively, in patients with pathological complete response, 38.6% and 71.9%, respectively, in patients with tumor downstaging, and 29.1 and 58.9% respectively, in patients with absence of response. A pretreatment carcinoembryonic antigen (CEA) level of <5 ng/ml was significantly independently associated with pathologic complete tumor response (p = 0.019). Pretreatment small tumor size (p = 0.04), pretreatment CEA level of <5 ng/ml (p = 0.008), and chemotherapy with capecitabine (vs. 5-FU) (p = 0.04) were significantly associated with tumor downstaging.
  
  
  CONCLUSIONS
  Downstaging and complete response after CRT improved progression-free survival and overall survival of locally advanced rectal adenocarcinoma. In multivariate analysis, a pretreatment CEA level of <5 ng/ml was associated with complete tumor response. Thus, small tumor size, a pretreatment CEA level of < 5 ng/ml, and use of capecitabine were associated with tumor downstaging.
authors.affiliation: Department of Radiation Oncology, Paoli-Calmettes Institute, Marseilles, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Moureau-Zabotto
authors.forename: Bertrand
authors.initials: B
authors.lastname: Farnault
authors.forename: Cecile
authors.initials: C
authors.lastname: de Chaisemartin
authors.forename: Benjamin
authors.initials: B
authors.lastname: Esterni
authors.forename: Bernard
authors.initials: B
authors.lastname: Lelong
authors.forename: Frederic
authors.initials: F
authors.lastname: Viret
authors.forename: Marc
authors.initials: M
authors.lastname: Giovannini
authors.forename: Genevieve
authors.initials: G
authors.lastname: Monges
authors.forename: Jean-Robert
authors.initials: JR
authors.lastname: Delpero
authors.forename: Erwan
authors.initials: E
authors.lastname: Bories
authors.forename: Olivier
authors.initials: O
authors.lastname: Turrini
authors.forename: Patrice
authors.initials: P
authors.lastname: Viens
authors.forename: Naji
authors.initials: N
authors.lastname: Salem
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage*; D000069287:Capecitabine; D002272:Carcinoembryonic Antigen / Q000097:blood; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy / Q000379:methods* / Q000401:mortality; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000964:Antimetabolites, Antineoplastic; D002272:Carcinoembryonic Antigen; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil