title: Molecular prognostic factors in locally irresectable rectal cancer treated preoperatively by chemo-radiotherapy.
abstract: OBJECTIVE
  The aim of this study was to determine the relationship between survival and value of molecular markers in the primary tumour in a group of patients with irresectable rectal cancer, treated with preoperative chemo-radiotherapy.
  
  
  METHODS
  Immunohistochemistry for p53, p21, bcl-2 and Ki-67 was performed on pre-treatment biopsy specimens of 34 patients with irresectable rectal cancer. Preoperative treatment consisted of pelvic irradiation of 45-56 Gy, combined with 5FU and leucovorin (350/20 mg/m2 x 5 d; in weeks 1 and 5 during radiotherapy). The median follow-up was 38 months. Endpoints were pathological T-stage and survival after surgery.
  
  
  RESULTS
  Expression of p21 correlated significantly with survival (p=0.005). Survival and p21 expression also correlated significantly, when adjusted for tumour response (p=0.005, RR=4.8 (1.6-14.7)).
  
  
  CONCLUSIONS
  Expression of p21 predicts a worse survival in irresectable rectal cancer treated with preoperative chemo-radiotherapy. No relationship was found between tumour response in chemo-radiotherapy and p53, bcl-2 or Ki-67.
authors.affiliation: Department of Radiotherapy Oncology, University Hospital Groningen, The Netherlands.
authors.forename: Onne
authors.initials: O
authors.lastname: Reerink
authors.forename: Arend
authors.initials: A
authors.lastname: Karrenbeld
authors.forename: John T M
authors.initials: JT
authors.lastname: Plukker
authors.forename: René C J
authors.initials: RC
authors.lastname: Verschueren
authors.forename: Ben G
authors.initials: BG
authors.lastname: Szabó
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Sluiter
authors.forename: Geke A P
authors.initials: GA
authors.lastname: Hospers
authors.forename: Nanno H
authors.initials: NH
authors.lastname: Mulder
mesh_terms: D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000096:biosynthesis* / Q000235:genetics; D020360:Neoadjuvant Therapy; D011300:Preoperative Care; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics; D012004:Rectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000628:therapy*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53