Predictors of Response to Chemo-radiotherapy and Radiotherapy for Esophageal Squamous Cell Carcinoma

Abstract

Background: The sensitivity of tumors to chemotherapy and radiotherapy differs from one case to another and may be influenced by the expression of biological molecules. The presence of six potential predictive markers in esophageal squamous cell carcinoma (ESCC) was investigated and the data obtained were related to the response of the tumors to chemo-radiotherapy and radiotherapy. Materials and Methods: Biopsy specimens were obtained from 61 patients with ESCC before treatment with chemo-radiotherapy (31 patients) or radiotherapy (30 patients). External radiotherapy was delivered by a two-field technique to a total of 60-70 Gray. Concurrent chemotherapy consisted of cisplatin or nedaplatin and 5-fluorouracil administered intravenously. The patients were examined before and after treatment by endoscopy, esophagography and computed tomography. The clinical response was classified as effective (>50% decrease in primary lesion), or ineffective. Immunohistochemical staining for p53, p21, bax, bcl2, heat-shock protein (Hsp) 27 and Hsp70 was performed on the biopsy specimens before therapy. Results: The primary tumor response was effective in 73.8% (45/61) and ineffective in 26.2% (16/61) of patients. Tumors with p53-positive expression were less sensitive than p53-negative tumors (p=0.033). p21-positive patients (p=0.027), and Hsp27-negative (p=0.0057) and Hsp70-negative patients (p=0.010) were all good responders. Neither bcl2 nor bax expression was related to the efficacy of therapy. Multivariate analysis revealed that Hsp27 was the most reliable predictor of the effect of chemo-radiotherapy and radiotherapy among the four potential markers. p53-negative and Hsp70-negative patients had a more favorable prognosis than p53- and Hsp70-positive patients (p=0.039, p=0.038, respectively). Conclusion: Expression of Hsp27 was a good predictor of the response of ESCC to chemo-radiotherapy and radiotherapy.