title: Epidermal growth factor receptor as a predictor of tumor downstaging in locally advanced rectal cancer patients treated with preoperative chemoradiotherapy.
abstract: OBJECTIVE
  To examine retrospectively whether levels of epidermal growth factor receptor (EGFR) expression can predict tumor downstaging after preoperative chemoradiotherapy in patients with locally advanced rectal cancer.
  
  
  METHODS
  A total of 183 patients with rectal cancer (cT3-T4 or N+) were enrolled in this study. Preoperative chemoradiotherapy consisted of 50.4 Gy of pelvic radiation with concurrent 5-fluorouracil and leucovorin bolus intravenous chemotherapy in 94 patients or oral capecitabine and leucovorin in 89 patients. EGFR expression in pretreatment paraffin-embedded tumor biopsy specimens was assessed by immunohistochemistry. EGFR expression was determined from the intensity and extent of staining. Tumor downstaging was defined as a reduction of at least one T-stage level.
  
  
  RESULTS
  Tumor downstaging occurred in 97 patients (53%), and the tumors showed a pathologic complete response in 27 patients (15%). Positive EGFR expression was observed in 140 (76%) of 183 patients. EGFR expression levels were low in 113 patients (62%) and high in 70 patients (38%). On logistic regression analysis, the significant predictive factor for increased tumor downstaging was a low level of EGFR expression and preoperative chemotherapy using oral capecitabine (odds ratio, 0.437; p = 0.012 vs. odds ratio, 3.235; p < 0.001, respectively).
  
  
  CONCLUSIONS
  A high level of EGFR expression may be a significant predictive molecular marker for decreased tumor downstaging after preoperative chemoradiotherapy in locally advanced rectal cancer.
authors.affiliation: Department of Radiation Oncology, Chungnam National University College of Medicine, Daejeon, Republic of Korea. k423j@cnu.ac.kr
authors.forename: Jun-Sang
authors.initials: JS
authors.lastname: Kim
authors.forename: Jin-Man
authors.initials: JM
authors.lastname: Kim
authors.forename: Shengjin
authors.initials: S
authors.lastname: Li
authors.forename: Wan-Hee
authors.initials: WH
authors.lastname: Yoon
authors.forename: Kyu-Sang
authors.initials: KS
authors.lastname: Song
authors.forename: Ki-Hwan
authors.initials: KH
authors.lastname: Kim
authors.forename: Seung-Gu
authors.initials: SG
authors.lastname: Yeo
authors.forename: Ji Sook
authors.initials: JS
authors.lastname: Nam
authors.forename: Moon-June
authors.initials: MJ
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism*; D000069287:Capecitabine; D003131:Combined Modality Therapy / Q000379:methods; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D002955:Leucovorin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology* / Q000532:radiotherapy; D012189:Retrospective Studies
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D003841:Deoxycytidine; D000069287:Capecitabine; D066246:ErbB Receptors; D002955:Leucovorin; D005472:Fluorouracil