Stratified medicine for cancer therapy.

As knowledge of the biological processes underlying malignant transformation becomes increasingly sophisticated, apparently similar diseases can be redefined according to the critical disrupted biological pathways and networks. The key genetic changes in most cancers can be mapped to one of a relatively few pathways, making it possible to classify tumours by their abnormal pathways and to identify potentially treatable--'druggable'--targets within these. The aim of the stratified approach to cancer therapy is to improve the effectiveness, tolerability and affordability of novel therapeutic agents.