目的　探讨bcl 2和P5 3基因蛋白在大肠癌发生中的作用和意义及其与大肠癌分级分期的关系。方法　采用免疫组织化学方法 ,检测bcl 2和P5 3蛋白在 2 6例大肠腺瘤和 12 5例大肠腺癌中的表达。结果　bcl 2蛋白在大肠腺瘤的阳性表达率为 76.9% ( 2 0 /2 6) ,在大肠腺癌为 65 .6% ( 82 /12 5 ) ,其阳性率有随肿瘤分化程度降低而随之下降的趋势 (P <0 .0 5 ) ,bcl 2蛋白阳性率随大肠癌分期的增高而下降 (P <0 .0 5 )。P5 3蛋白仅在 1例重度非典型增生的大肠腺瘤有阳性表达 ( 3 .8% ) ,而在大肠腺癌的阳性表达率达 80 % ( 10 0 /12 5 ) ,但其阳性率与肿瘤的分化程度和肿瘤分期无递增递减规律。 46.4% ( 5 8/12 5 )的腺癌有bcl 2和P5 3蛋白的共同表达。两种蛋白的阳性表达率存在负相关 (rs =-0 .68,P <0 .0 5 )。结论　bcl 2基因在大肠癌发生发展的早期阶段起作用 ,而P5 3蛋白的过表达可能在大肠癌发生发展的晚期阶段。bcl 2和P5 3基因蛋白的联合检测可以作为临床早期判断大肠腺瘤癌变的一个重要参考指标 Objective To investigate the role and significance of bcl 2 and P53 gene protein in the development of colorectal cancer and its relationship with the staging of colorectal cancer. Methods Immunohistochemistry was used to detect the expression of bcl 2 and P53 protein in 26 cases of colorectal adenoma and 125 cases of colorectal adenocarcinoma. Results The positive expression rate of bcl 2 protein in colorectal adenomas was 76.9% (2 0 /26), and in colorectal adenocarcinoma 65.6% (82/12 5). The positive rate of bcl 2 protein decreased with the degree of tumor differentiation. With a decreasing trend (P < 0.05), the positive rate of bcl-2 protein decreased with the increase of the stage of colorectal cancer (P < 0.05). P5 3 protein was only positively expressed in one case of severe adenoid adenocarcinoma (3.8%), while the positive expression rate in colorectal adenocarcinoma was 80% (10 0 /12 5 ), but the positive rate was The degree of differentiation of the tumor and the stage of the tumor did not increase gradually. 46.4% (5 8/12 5) of adenocarcinomas had co-expression of bcl 2 and P5 3 proteins. There was a negative correlation between the positive expression rates of the two proteins (rs = -0.68, P < 0.05). Conclusion The bcl 2 gene plays an important role in the early stage of the development of colorectal cancer, while the overexpression of P53 protein may be in the late stage of the development of colorectal cancer. Combined detection of bcl 2 and P5 3 gene proteins may serve as an important reference for the early diagnosis of colorectal adenomas