In this study, we attempted to see the expression of Cyclin D1 in invasive ductal carcinomas of the breast in our population and correlate its expression with other known prognostic parameters.
Our observation showed that cyclin D1 was strongly positive in 61% (14/23) of the comedo subtype, 61% (11/18) of the non-comedo subtype, 59% (24/41) of the comedo DCIS and 63% (26/41) of the adjacent invasive ductal carcinomas, 53% (10/19) of the non-comedo DCIS and 58% (11/19) of the adjacent invasive lesions, 58% (157/270) of the invasive ductal carcinomas, 73% (24/33) of the invasive lobular carcinomas, 52% (11/21) of the colloid carcinomas and 27% (4/15) of the medullary carcinomas.
We looked for cyclin D1 gene amplification and protein overexpression in 30 cases of benign breast disease (16 epithelial hyperplasias without atypia and 14 atypical ductal hyperplasias) and 18 ductal carcinomas in situ by use of differential PCR and immunohistochemical staining.
In this study, cyclin D1 was detected immunohistochemically in approximately one-third of infiltrating ductal carcinomas; approximately one-third of these had detectable cyclin D1 gene amplification.
In contrast, pronounced overexpression/nuclear accumulation of cyclin D1 was found in 37 per cent of cases in a series of 35 primary ductal carcinomas of the breast.