Changing concepts in the pathological basis of soft tissue and bone sarcoma treatment.

Though soft tissue sarcomas are rare considerable progress has been made in the clinical and biological understanding of these neoplasms. This has led to the launch of a new WHO classification of soft tissue tumours in 2002, which integrate morphological data with tumour specific (cyto-) genetics. Moreover worldwide consensus has grown how to predict clinical behaviour based on a specific grading system and which specific types of tumours seem not to obey these rules. As a consequence entry criteria for multi-institute prospective trials have changed over the last few years. The recent identification of tumour specific drug targets by immunohistochemistry has had impact on specimen requirements and handling as well as laboratory standards. These changes in concepts, classification, and processing of soft tissue sarcomas have had impact on patient selection and treatment and formats of multi-institute trials.