[Beyond staging, typing and grading. New challenges in breast cancer pathology]

Tumor biological parameters for the prediction and prognosis of invasive breast cancer are gaining in importance compared to traditional pathological categories. The immunohistochemically determined steroid hormone receptor status is not only the decisive factor influencing whether endocrine therapy (which is indicated in cases of even slight expression) is given or not, but also whether chemotherapy is considered. The Her2 status is of similar importance and needs to be analysed in every case of invasive carcinoma, whereby reproducibility, which requires greater efforts than with steroid hormone receptors, has to be assured. Probably only a small portion of breast cancers will benefit from chemotherapy. Since traditional pathological categories are not sufficient for the identification of this subgroup, there has been an intense search for alternative prognostic parameters, whereby gene expression profiling has emerged as the most promising tool. Despite minimal concordance with regard to single genes, the various profiles available converge in the identification of the proliferative signature as the prognostically most relevant. Whether histopathological grading and immunohistochemical determination of the growth fraction with Ki-67 or genetic profiling will be more reliable in the identification of the aggressive subtype has yet to be clarified in clinical studies which encompass central pathological review.