title: Expression of p53, p21 and p16 does not correlate with response to preoperative chemoradiation in gastric carcinoma.
abstract: OBJECTIVE
  A retrospective evaluation was oerformed to determine whether the intensity of p53, p21 or p16 expression predicts response to preoperative chemoradiotherapy in locally advanced gastric carcinoma.
  
  
  METHODS
  Thirty-six patients (cT2-4 or N+) were studied. Preoperative treatment consisted of 30-45Gy of radiation with continuous 5-fluorouracil and weekly cisplatin. Expression of p53, p21 and p16 in pretreatment biopsies was assessed by immunohistochemistry. Level of expression was determined from the intensity and extent of staining. Tumor downstaging was defined as a reduction of at least one T-stage level and/or finding of intense tumor regression in histopathologic examination.
  
  
  RESULTS
  Seventeen patients responded to chemoradiation: 8 patients had pathologic complete response, 9 patients were downstaged. The multivariate analysis showed no significant influence of p53 (p = 0.76), p21 (p = 0.10) nor p16 (p = 0.70) expression upon tumor response. Response was found in 52% of patients with low, and in 40% of patients with high p53 staining (p = 0.21); in 54% of patients with low, and in 30% of patients with high p21 staining (p = 0.14); and in 48% of patients with low, and in 43% of patients with high p16 staining (p = 0.32).
  
  
  CONCLUSIONS
  We found no significant influence of p53, p21 nor p16 expression upon response to preoperative chemoradiotherapy in gastric carcinoma.
authors.affiliation: Department of Oncology and Radiotherapy, Charles University Medical School and University Hospital, Hradec Kralove, Czech Republic. sirak@fnhk.cz
authors.forename: Igor
authors.initials: I
authors.lastname: Sirak
authors.forename: Jiri
authors.initials: J
authors.lastname: Petera
authors.forename: Jana
authors.initials: J
authors.lastname: Hatlova
authors.forename: Milan
authors.initials: M
authors.lastname: Vosmik
authors.forename: Bohuslav
authors.initials: B
authors.lastname: Melichar
authors.forename: Josef
authors.initials: J
authors.lastname: Dvorak
authors.forename: Vera
authors.initials: V
authors.lastname: Tycova
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Zoul
authors.forename: Michal
authors.initials: M
authors.lastname: Lesko
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D016009:Chi-Square Distribution; D003131:Combined Modality Therapy; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009367:Neoplasm Staging; D011300:Preoperative Care; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53