title: Is there a correlation between molecular markers and response to neoadjuvant  chemoradiotherapy in locally advanced squamous cell esophageal cancer?
abstract: OBJECTIVE
  To evaluate the expression of epidermal growth factor receptor (EGFR), p53, p21 and thymidylate synthase (TS) in a pretherapy biopsy specimen of locally advanced squamous cell esophageal cancer and correlate these markers with response to neoadjuvant chemoradiotherapy.
  
  
  METHODS
  Sixty-two patients with histopathologically proven locally advanced (T3 or greater) squamous cell esophageal cancer were enrolled. The expression of EGRF, p53, p21 and TS markers was assessed with immunohistochemistry. Semiquantitative assessment of expression of these markers was performed based on the percent of the stained cells. Radiotherapy (45-50.4 Gy) was delivered concomitantly with 5-fluorouracil (5-FU)/leucovorin (LV)/cisplatin (CIS) chemotherapy. Five to 6 weeks after chemoradiation, response to treatment was assessed. Medically fit and operable patients were operated. The resected material underwent histopathological evaluation of tumor expansion, histological classification after initial multimodality treatment (yp TNM), residual status and tumor regression grade (TRG).
  
  
  RESULTS
  Out of 62 patients enrolled, 41 (66%) were evaluated for molecular markers. Clinical response rate was 43.9%. Out of 41 patients, 12 (29%) underwent surgery. TRG 1 was noted in 58% of the patients. In a pretherapy tumor specimen, positive expression was noted in 80, 90, 80 and 71% for EGFR, p53, p21 and TS, respectively. We noted no statistically significant difference neither between tumor marker expression and clinical response to chemoradiation, nor between tumor marker expression and TRG.
  
  
  CONCLUSIONS
  We registered no difference in response to treatment between EGFR, TS, p21 and p53 positive and negative staining.
authors: Clinic for Radiation Oncology and Diagnostics, Department of Radiation Oncology, Institute for Oncology and Radiology of Serbia, Belgrade, Serbia. marijarhi@yahoo.com
authors: T
authors: T
authors: Arsenijevic
authors: M
authors: M
authors: Micev
authors: V
authors: V
authors: Nikolic
authors: D
authors: D
authors: Gavrilovic
authors: S
authors: S
authors: Radulovic
authors: P
authors: P
authors: Pesko
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000628:therapy*; D059248:Chemoradiotherapy; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000032:analysis; D066246:ErbB Receptors / Q000032:analysis; D004938:Esophageal Neoplasms / Q000737:chemistry / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D013940:Thymidylate Synthase / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016159:Tumor Suppressor Protein p53; D013940:Thymidylate Synthase; D066246:ErbB Receptors