title: Predictive factors of complete response to neoadjuvant chemoradiotherapy in patients with rectal cancer.
abstract: OBJECTIVE
  Pathological complete response (pCR) after neoadjuvant chemoradiotherapy is a favorable prognosticator in rectal cancer patients. We investigated whether the biological features of the primary tumor affect pCR.
  
  
  METHODS
  Forty-six patients treated with capecitabine-oxaliplatin and pelvic conformal radiotherapy were considered. Forty-three patients underwent surgery, and the pathologic response was scored according to the tumor regression grade (TRG) scale. Epidermal growth factor receptor (EGFR), vascular endothelial growth factor, poly(adenosine diphosphate-ribose) polymerase-1, X-ray cross-complimenting, thymidylate synthase (TS) and Ki67 expression were evaluated by immunohistochemistry on rectal biopsies obtained before chemoradiotherapy, and scored as the percentage of positive cells. Cutoffs were selected based on ROC analysis. The correlation between the biological factors and the TRG coded as TRG1 (pCR) versus TRG ≥2 (no pCR) was assessed by the χ(2) test and logistic regression analysis.
  
  
  RESULTS
  Low EGFR (p = 0.007), high TS (p = 0.002), and high Ki67 (p = 0.05) were strongly associated with pCR. Upon univariate analysis, TRG significantly affected disease-free survival (p = 0.03).
  
  
  CONCLUSIONS
  pCR was significantly associated with high TS, high Ki67 and low EGFR expression. Patients with pCR have a significantly lower incidence of relapse.
authors.affiliation: Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Università Federico II, Napoli, Italia. chiara.carlomagno@unina.it
authors.forename: Chiara
authors.initials: C
authors.lastname: Carlomagno
authors.forename: Stefano
authors.initials: S
authors.lastname: Pepe
authors.forename: Francesco Paolo
authors.initials: FP
authors.lastname: D'Armiento
authors.forename: Maria
authors.initials: M
authors.lastname: D'Armiento
authors.forename: Lucia
authors.initials: L
authors.lastname: Cannella
authors.forename: Alfonso
authors.initials: A
authors.lastname: De Stefano
authors.forename: Anna
authors.initials: A
authors.lastname: Crispo
authors.forename: Marcella
authors.initials: M
authors.lastname: Giordano
authors.forename: Sabino
authors.initials: S
authors.lastname: De Placido
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D003113:Colonoscopy; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D000077150:Oxaliplatin; D011237:Predictive Value of Tests; D011878:Radiotherapy; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D012044:Regression Analysis; D015996:Survival Rate
chemical_list: D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin