title: Update on molecular findings in rhabdomyosarcoma.
abstract: Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumour in children and adolescents. Histologically RMS resembles developing fetal striated skeletal muscle. RMS is stratified into different histological subtypes which appear to influence management plans and patient outcome. Importantly, molecular classification of RMS seems to more accurately capture the true biology and clinical course and prognosis of RMS to guide therapeutic decisions. The identification of PAX-FOXO1 fusion status in RMS is one of the most important updates in the risk stratification of RMS. There are several genes close to PAX that are frequently altered including the RAS family, FGFR4, PIK3CA, CTNNB1, FBXW7, and BCOR. As with most paediatric blue round cell tumours and sarcomas, chemotherapy is the key regimen for RMS therapy. Currently there are no direct inhibitors against PAX-FOXO1 fusion oncoproteins and targeting epigenetic cofactors is limited to clinical trials. Failure of therapy in RMS is usually related to drug resistance and metastatic disease. Through this review we have highlighted most of the molecular aspects in RMS and have attempted to correlate with RMS classification, treatment and prognosis.
authors.affiliation: Faculty of Medicine, University of Ottawa, Ontario, Canada; Pediatric Pathology, Children's Hospital of Eastern Ontario, Ontario, Canada. Electronic address: deldemellawy@cheo.on.ca.
authors.forename: Dina
authors.initials: D
authors.lastname: El Demellawy
authors.affiliation: Faculty of Medicine, University of Ottawa, Ontario, Canada; Genetics, Children's Hospital of Eastern Ontario, Ontario, Canada.
authors.forename: Jean
authors.initials: J
authors.lastname: McGowan-Jordan
authors.affiliation: Faculty of Medicine, University of Ottawa, Ontario, Canada; Pediatric Pathology, Children's Hospital of Eastern Ontario, Ontario, Canada.
authors.forename: Joseph
authors.initials: J
authors.lastname: de Nanassy
authors.affiliation: Faculty of Medicine, University of Ottawa, Ontario, Canada.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Chernetsova
authors.affiliation: Faculty of Medicine, University of Ottawa, Ontario, Canada; Pediatric Surgery, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Nasr
mesh_terms: D000818:Animals; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D018482:Muscle, Skeletal / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000378:metabolism*; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D011379:Prognosis; D012208:Rhabdomyosarcoma / Q000145:classification / Q000175:diagnosis* / Q000473:pathology*
chemical_list: D051858:Forkhead Transcription Factors; D015514:Oncogene Proteins, Fusion; D051761:Paired Box Transcription Factors
keywords: PAX-FOXO1 fusion; Rhabdomyosarcoma; epigenetics; molecular pathology; paediatric sarcoma; targeted therapy