Abstract:【Objective】 To assume that insulin -like growth factor binding protein -3 (IGFBP -3) has an effect on radiotherapeutic effect and prognosis for esophageal squamous cell carcinoma (ESCC). The present study was designed to investigate the clinical and prognostic significance of IGFBP -3 in ESCC patients. 【Methods】 IGFBP -3 was detected by immunohistochemistry (IHC) in paraffin -embedded tissues from 70 ECSS patients who treated with radiotherapy alone. IGFBP -3 was further examined by western blotting analysis in 10 pair of fresh ESCC tissues and adjacent non -malignant esophageal specimens. Differences in IGFBP -3 expression and clinical characteristics were compared byχ2 test. Correlations between prognostic outcomes and with IGFBP -3 expression were investigated using Kaplan╞Meier analysis and the Cox proportional hazards model. 【Result】 45.7% (32 of 70) ESCC tissues were defined as having a high expression of IGFBP -3. 70% ESCCs had reduced levels of IGFBP -3 protein expression compared with adjacent non -malignant esophageal tissue. In addition

IGFBP -3 expression is correlated with pathological classification (P < 0.05 for T

N

and M classifications and clinical stages). 【Conclusion】 Patients with higher levels of IGFBP -3 had a better radiotherapy effect and prolonged overall survival (P < 0.001). Higher level of IGFBP -3 expression may be a positive factor for advanced clinicopathological classification and prolonged patient survival. Our data suggest that IGFBP -3 may serve as a potential predictor for radiosensitivity and prognostic evaluation in ESCC patients treated with RT.