Prognostic and Predictive Factors

In this chapter, the pathological features that are used in assessing the prognosis of breast cancer patients and predicting the tumor response to therapeutic agents are discussed. These features include classic pathological parameters: tumor size, lymph node status, tumor grade, histopathological types, and lymphovascular invasion. Other pathological parameters are usually determined by immunohistochemical and/or in situ hybridization methods, namely, steroid hormone receptor and HER2 (c-erb B-2) analysis. The role of assessing the proliferative activity of breast carcinomas by Ki-67 and its limitations are discussed. Molecular profiling and gene expression tests in breast carcinoma and their use, advantages and disadvantages are also discussed. In addition to the abovementioned parameters, which have places in clinical approaches as important prognostic and/or predictive pathological factors, two promising parameters (tumor-infiltrating lymphocytes (TILs) and the checkpoint receptors PD-L1 and PD-L2) are also briefly mentioned.