Biomarkers of response to molecular targeted therapy in renal cell carcinoma

Therapeutic options for metastatic renal cell carcinoma (mRCC) have been evolving rapidly, with the approval of a variety of effective molecular targeted agents. With increasing choices of treatment modalities that may potentially improve survival, it is of great clinical benefit to be able to predict the clinical outcome of mRCC patients treated with molecular targeted agents. In addition, predictors of severe adverse events are warranted since those molecular targeted agents present a toxicity profile that is very different from that of conventional chemotherapeutic agents. Their use requires knowledge of a large number of possible adverse events. Although validation of previous criteria, such as the Motzer criteria, is important, a further implementation of RCC molecular biology knowledge would be ideal for finding a new predictive marker in this new age of molecular targeted therapies. The most prominent biomarker is vascular endothelial-derived growth factor (VEGF). Those patients who presented low serum VEGF showed prolonged progression-free survival when treated with sunitinib. Genetic markers such as single nucleotide polymorphisms (SNPs) are continuously being validated as markers, predicting molecular targeted therapy response as well as severe adverse events. The identification of biomarkers that predict response or severe adverse events from molecular targeted agents will aid in patient selection and guide therapy development.