New prognostic histological parameter of invasive ductal carcinoma of the breast: Clinicopathological significance of fibrotic focus

Immunohistochemistry, DNA ploidy analysis and molecular genetics have made it possible to predict the outcome of breast cancer more precisely than rou tine histological examination alone. However, in routine practice, it is di fficult to incorporate these methodologies in all cases. If certain histolo gical parameters can accurately predict the outcome of patients with breast cancer, they would be more practical for routine use. We showed that the p resence of fibrotic focus (FF) in invasive ductal carcinoma (IDC) is closel y associated with c-erbB-2 or p53 protein expression, high proliferative ac tivity, and high angiogenesis of the tumors. Furthermore, multivariate anal yses with well-known prognostic parameters for IDC demonstrated that the pr esence of FF is the most useful independent parameter to predict IDC patien t outcome. In addition, our data suggested that the interaction between tum or cells and stromal fibroblasts may play an important role in the formatio n of FF in IDC based on growth factor and growth factor receptor protein ex pression in the tumor cells and fibroblasts forming FF. Based on the result s of our clinicopathological studies, we propose a new prognostic classific ation scheme for the prediction of IDC patient outcome, which consists of F F, nuclear atypia, and fat invasion. This classification has superior predi cting power to existing prognostic classifications.