Influence of preoperative chemoradiotherapy on changes of epidermal growth factor receptor expression in patients treated by preoperative chemoradiotherapy for local advanced rectal carcinoma

The aim of this retrospective study was to determine the prognostic impact of expression of epidermal growth factor receptor (EGFR) changes during neoadjuvant chemoradiotherapy in patients with locally advanced rectal adenocarcinoma. One hundred and three patients with locally advanced rectal adenocarcinoma of stage II and III were evaluated. All patients were administered the total dose of 44 -- 50.4 Gy. Concomitantly, the patients received capecitabine in the dose 825 mg/ m² in two daily oral administrations or 5- fluorouracil in the dose 200 mg/ m² in continuous infusion. Surgery was indicated at intervals of 4-8 weeks from chemoradiotherapy completion. EGFR expression in the pretreatment biopsies and in resected specimens was assessed with immunohistochemistry. All of 103 patients received radiotherapy without interruption up to the total planned dose. Downstaging was described in 64 patients. Six patients had complete pathologic remission. Recurrence occurred in 49 patients. Local recurrence was found in 22 patients, generalization of disease was reported in 27 patients. A total of 51 patients died. Increased EGFR expression was found in 26 patients. The statistically significantly shorter overall survival (p < 0.001) and disease-free survival (p < 0.001) was found in patients with increased expression of EGFR compared with patients where no increase in the expression of EGFR was observed during neoadjuvant chemoradiotherapy. The overexpression of EGFR during neoadjuvant chemoradiotherapy for locally advanced rectal adenocarcinoma is associated with significant shorter overall survival and disease-free survival.