title: Comprehensive analysis of published studies involving systemic treatment for chondrosarcoma of bone between 2000 and 2013.
abstract: BACKGROUND
  The majority of patients with chondrosarcoma of bone have an excellent overall survival after local therapy. However, in case of unresectable locally advanced or metastatic disease the outcome is poor and limited treatment options exist. Therefore we conducted a survey of clinical phase I or II trials and retrospective studies that described systemic therapy for chondrosarcoma patients.
  
  
  METHODS
  Using PubMed, clinicaltrials.gov, the Cochrane controlled trial register and American Society of Clinical Oncology (ASCO) abstracts a literature survey was conducted. From the identified items, data were collected by a systematic analysis. We limited our search to semi-recent studies published between 2000 and 2013 to include modern drugs, imaging techniques and disease evaluations.
  
  
  RESULTS
  A total of 31 studies were found which met the criteria: 9 phase I trials, 11 phase II and 8 retrospective studies. In these studies 855 chondrosarcoma patients were reported. The tested drugs were mostly non-cytotoxic, either alone or in combination with another non-cytotoxic agent or chemotherapy. Currently two phase I trials, one phase IB/II trial and three phase II trials are enrolling chondrosarcoma patients.
  
  
  CONCLUSIONS
  Because chondrosarcoma of bone is an orphan disease it is difficult to conduct clinical trials. The meagre outcome data for locally advanced or metastatic patients indicate that new treatment options are needed. For the phase I trials it is difficult to draw conclusions because of the low numbers of chondrosarcoma patients enrolled, and at different dose levels. Some phase II trials show promising results which support further research. Retrospective studies are encouraged as they could add to the limited data available. Efforts to increase the number of studies for this orphan disease are urgently needed.
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: Annemiek M
authors.initials: AM
authors.lastname: van Maldegem
authors.affiliation: Department of Pathology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Judith Vmg
authors.initials: JV
authors.lastname: Bovée
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Gelderblom
keywords: Chondrosarcoma; Clinical trial; Systemic treatment