title: Clinical biomarkers of kinase activity: examples from EGFR inhibition trials.
abstract: BACKGROUND
  Tumor response and duration of patient survival after treatment with inhibitors of the epidermal growth factor receptor (EGFR) varies considerably between different kinds of EGFR inhibitors, different combination schedules, but also between individual patients.
  
  
  CONCLUSIONS
  Development and introduction of biomarkers into clinical practice is necessary to predict treatment response and thereby to individualize cancer therapy. Due to specific interactions of EGFR inhibitors with biological effects of irradiation, biomarkers are expected to differ for radiation oncology compared to application of the drugs alone or within chemotherapy treatment schedules and therefore need to be established and tested separately.
  
  
  OBJECTIVE
  The review summarizes the current status of potential predictors for the effect of EGFR inhibitors used as single agents or in combination with chemotherapy.
  
  
  CONCLUSIONS
  Based on this knowledge and on preclinical radiotherapy data, candidate biomarkers and further research strategies for radiation oncology are discussed.
authors.affiliation: Department of Radiation Oncology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany. mechthild.krause@tu-dresden.de
authors.forename: Mechthild
authors.initials: M
authors.lastname: Krause
authors.forename: Michael
authors.initials: M
authors.lastname: Baumann
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002986:Clinical Trials as Topic; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy*; D010770:Phosphotransferases / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D004791:Enzyme Inhibitors; D010770:Phosphotransferases; D066246:ErbB Receptors