Nearly 29,000 scientists from all over the world gathered at the 41st Annual Meeting of the American Society of Clinical Oncology (ASCO). The programme included the presentation of new data encompassing all the fields of cancer research, including cancer prevention, treatment and biology. Special sessions were added to summarise and discuss achievements in the field of translational research on biologically targeted therapies. Rational drug design based on tumour biology and genetics represents a promising strategy to overcome the limitations of conventional chemotherapy. Increased knowledge in the field of molecular oncology, genetics and progress in technology are revolutionising tumour classification, prognostication, prediction and therapy. However, at present, for most of the diseases, improvements brought about by the newer therapies are small, although clinically meaningful. This review will briefly address some of the most interesting data presented at ASCO 2005.