The Expression of ras Oncogene in Benign and Malignant Lesions of Breast

ABSTRACT

To evaluate correlation between the amount of oncogene products in tumor cell extracts and malignant potentiality in breast tumor, immunohistochemical staining for the ras Oncogene products was performed in the sections of benign and malignant lesions of the breast. The results obtained were as follows 1) The positive reaction to ras Oncogene products was usually observed in the cytoplasm and cell membrane. 2) The ratio of positive reaction was 30.4% in epithelial hyperplasia of fibrocystic disease, 26.5% in fibroadenoma. 49.5% in intraductal carcinoma 71.6% in infiltrating ductal carcinoma, 85.2% in metastatic infiltrating ductal carcinoma, and 89.7% in relatively preserved neighboring lobules of infiltrating ductal carcinoma. In conclusion, the ras oncogene products are found by a significantly higher ratio in the more aggressive lesions, and the infiltrating ductal carcinoma might represent its potential of malignant transformation. 3) The expression of ras oncogene was heterogeneous in primary as well as metastatic mammary carcinomas.