Expression of Epidermal Growth Factor Receptor as A Predictive Factor for Rectal Cancer

Background: Expression of epidermal growth factor receptor is observed in 50 – 70 % of colorectal carcinomas and is associated with poor prognosis. The objective of this study was to analyze whether epidermal growth factor receptor expression predicts tumor response and sphincter preserving in patients treated with preoperative chemoradiation therapy. Methods: This study was conducted on 34 patients with locally-advanced rectal adenocarcino-ma who were treated with preoperative chemoradiation therapy. The patients had histologically-proven adenocarcinoma of the rectum with the inferior margin of the tumor located no farther than 6 cm from the anal verge. Preoperative radiotherapy was delivered to the pelvis with 60CO to 50.4 Gy. All patients received simultaneous chemotherapy with 5-fluorouracil, 300 mg/m2 IV infused over 24 hr during radiotherapy on days 1 – 5 every week; 28 patients received oxaliplatin 50 – 60 mg/m2 weekly during radiotherapy. The patients were restaged by physical examination and pelvic CT, between four and six weeks later. Then, they were referred to a surgeon who was expert in gastrointestinal cancer surgery. Subsequently, postsurgical specimen was histopathologically examined and graded according to the Mandard criteria for assessment of pathologic response after neo-adjuvant chemoradiation. Immunohistochemistry for epidermal growth factor recepto