| Abstract: | The pathological characterization of breast cancers today extends beyond traditional typing, staging, and grading. Via immunohistochemistry, intrinsic subtypes, luminal A and B, HER2, and triple-negative types can be determined, which in most cases has a greater impact for the prognosis and prediction of therapy than does traditional histologic typing and stage. With regard to the luminal subtypes, the proliferation marker Ki67 provides a frequently used tool for discriminating between the prognostically favorable A type, which can be sufficiently treated by endocrine therapy alone, from the unfavorable B type, which will need additional chemotherapy. However, with Ki67 there is no commonly accepted threshold for low and high risk. Gene expression profiles are increasingly used for a more precise evaluation of prognosis in breast cancer. Different gene expression profiles are available that reveal only a moderate congruence in risk prediction. Neoadjuvant concepts of therapy with preoperative cytotoxic or endocrine medication offer the opportunity to evaluate the in vivo response of tumors. Complete and partial pathological remission after chemotherapy or dynamic Ki67 reduction following endocrine therapy represents new prognostic and predictive markers provided by pathological tissue examination. |
