[Resistance to medicinal tumor therapy. Current status].

In the past multiple mechanisms could be identified that are involved in anticancer drug resistance; however, diagnostic assays for prediction of therapy response to classical cytostatic drugs did not enter routine clinical diagnostics. Only when new targeted drugs, e.g. tyrosine kinase inhibitors or therapeutic antibodies, were introduced in oncology were diagnostics for prediction of therapy response routinely preformed. First and foremost this was the result of the development of highly standardized techniques, i.e. exact mutation analysis in functional relevant codons of genes encoding signal proteins of cancer-related signal transduction pathways targeted by the new drugs. Due to increasing costs of health systems, in the future predictive diagnostics will probably become more and more important. Therefore, it will be necessary to develop improved diagnostic assays for prediction of individual therapy response.