Abstract: In order to study the expression of bcl - 2 , p53 protein in laryngeal squmaous cell carcinoma (LSCC) , the prognostic significance , their expression in 53 cases with laryngeal squmaous cell carcinoma were determinded by immunohistochemical LSAB method. The result s showed that : (1) In 47. 17 %LSCC , the expression of mutant p53 protein were positive. Meanwhile , mutant p53 protein was also expressed in some dysplastic epitheliumes near the cancer tissues. These epithelial cells near the tumor in which p53 gene has been altered , probably are the source of tumor recurrence , the expression of mutant p53 protein may be the early event s in the development of LSCC. The p53 protein expression was associated with low histological grade of differentiation , high mitotic count ( ( P < 0. 05 , P < 0. 01) . The necrosis in tumors with the p53 positive was higer than those with the P53 negative LSCC( P < 0. 01) ,patient s with p53 - positive LSCC had shorter survival times than patient s with p53 - negative LSCC. p53 protein expression was not associated with node status and age , is valuable in determinding the degree of malignancy , predicting tumor differentiation (2) In LSCCs , bcl - 2 expression was consistently low and related with low mitotic count and younge age ( P < 0. 05 , P < 0. 05) ,and bcl - 2 expression was not related with histological grade of differentiation , necrosis , node status and survival time.

Key words: bcl - 2, p53, Immunohistochemist ry, laryngeal carcinoma, prognosis