[Clinicopathological and genomics predictors of response to neoadjuvant chemotherapy in breast cancer]

Breast cancer is a frequent and heterogeneous disease. The choice of systemic treatments such as chemotherapy is based on predicting factors of response that did not much evolve. Preoperative chemotherapy provides an opportunity to directly assess tumor response to therapy. Predictors based on mathematical models could optimize those treatments. To go on this way, three different concepts have been developed to predict the preoperative chemotherapy complete response. Predictors based on clinical and pathological variables are specific of a tumor. They combine into mathematical models variables that have been previously identified as predicting the preoperative chemotherapy complete response. Predictors based on gene expression profile have been developed from groups of patients who received preoperative chemotherapy. They integrate multigene information to predict the tumor behaviour in front of several cytotoxic agents. Those predictors developed for each type of drug characterize the genetic chemoresistance of a tumor. In the same time, predictors of chemosensitivity developed from cell lines of diverse human cancer appeared. The authors established a genetic profile involved into chemoresistance and extrapolated the drug sensitivity for another type of cancer which was not represented, as breast cancer. All those predictors seem interesting but evolution of patients' characteristics and treatments induces a perpetual reassessment to optimize our predictive abilities.