Gastrointestinal cancer: towards a tailored tumour therapy.

Major progress has been made in the treatment of metastatic colorectal cancer, but conventional chemotherapy is unlikely to lead to a major breakthrough in the treatment of gastrointestinal tumours. Prognosticators, novel means of early diagnosis of cancer which at the same time indicate prognosis, as well as novel, tumour-specific therapeutic strategies, are urgently needed. There is an increasing amount of promising data from array technology and functional proteomics suggesting that this goal could be achieved in the near future. Research into the mechanisms of cancer signal transduction over the past 20 years has enabled the identification of numerous novel targets for tumour therapy and subsequently the development of various novel drugs termed magic bullets. The in vitro results with these drugs are promising; many drugs lost their magic after the first clinical trials. The state of novel diagnostics and therapeutics in gastrointestinal cancer and the implications for the future treatment of these tumours are discussed in this review.