title: Endosialin expression in soft tissue sarcoma as a potential marker of undifferentiated mesenchymal cells.
abstract: Soft tissue sarcomas are a group of neoplasms with differentiation towards mesenchymal tissue, many of which are aggressive and chemotherapy resistant. Histology and immunoprofiles often overlap with neoplasms of other lineages, and establishing an accurate histopathological diagnosis is crucial for correct management, and therapeutic stratification. The endosialin cell surface glycoprotein is predominantly expressed by stromal fibroblasts and pericytes in epithelial neoplasms; however, tumour cell expression has been reported in small series of sarcomas.
  
  
  
  We assessed endosialin expression by immunohistochemistry in a large set of 514 human soft tissue sarcomas.
  
  
  
  Tumour cell endosialin expression was seen in 89% of undifferentiated pleomorphic sarcomas (104/117), 77% adult fibrosarcomas/spindle cell sarcomas (20/26), 62% synovial sarcomas (37/60), 51% leiomyosarcomas (94/185) and 31% rhabdomyosarcomas (39/126).
  
  
  
  Endosialin immunohistochemistry has potential to distinguish undifferentiated and poorly differentiated sarcomas from other poorly differentiated, non-mesenchymal neoplasms. A Phase II trial randomising patients with advanced sarcomas to receive chemotherapy with/without an endosialin therapeutic antibody has recently completed enrolment. Endosialin expression could be used to select patients for such clinical trials. Based on our results, patients with undifferentiated pleomorphic sarcoma may be particularly suitable for such a therapeutic approach.
authors.affiliation: Sarcoma Unit, The Royal Marsden NHS Foundation Trust, 203 Fulham Road, London SW3 6JJ, UK.
authors.forename: Khin
authors.initials: K
authors.lastname: Thway
authors.affiliation: The Breast Cancer Now Research Centre, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
authors.forename: David
authors.initials: D
authors.lastname: Robertson
authors.affiliation: Sarcoma Unit, The Royal Marsden NHS Foundation Trust, 203 Fulham Road, London SW3 6JJ, UK.
authors.forename: Robin L
authors.initials: RL
authors.lastname: Jones
authors.affiliation: Sarcoma Molecular Pathology Team, Divisions of Molecular Pathology and Cancer Therapeutics, The Institute of Cancer Research, Sutton, Surrey SM2 5NG, UK.
authors.forename: Joanna
authors.initials: J
authors.lastname: Selfe
authors.affiliation: Sarcoma Molecular Pathology Team, Divisions of Molecular Pathology and Cancer Therapeutics, The Institute of Cancer Research, Sutton, Surrey SM2 5NG, UK.
authors.forename: Janet
authors.initials: J
authors.lastname: Shipley
authors.affiliation: Sarcoma Unit, The Royal Marsden NHS Foundation Trust, 203 Fulham Road, London SW3 6JJ, UK.
authors.forename: Cyril
authors.initials: C
authors.lastname: Fisher
authors.affiliation: The Breast Cancer Now Research Centre, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
authors.forename: Clare M
authors.initials: CM
authors.lastname: Isacke
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000378:metabolism*; D000072645:Cancer-Associated Fibroblasts / Q000378:metabolism; D005354:Fibrosarcoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000378:metabolism* / Q000473:pathology; D020286:Pericytes / Q000378:metabolism; D012208:Rhabdomyosarcoma / Q000378:metabolism* / Q000473:pathology; D018232:Rhabdomyosarcoma, Alveolar / Q000378:metabolism / Q000473:pathology; D018233:Rhabdomyosarcoma, Embryonal / Q000378:metabolism / Q000473:pathology; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology; D013584:Sarcoma, Synovial / Q000378:metabolism* / Q000473:pathology
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; C078203:CD248 protein, human