title: Clear cell sarcoma of the kidney: patients' characteristics and improved outcome in developing countries.
abstract: BACKGROUND
  Clear cell sarcoma of the kidney (CCSK) is a rare and aggressive tumor accounting for 5% of pediatric renal tumors with an incidence of 20 patients per year in the USA. It is bone metastasizing with poor prognosis. Our aim was to show characteristics of patients in relation to improved outcome in one of the developing countries.
  
  
  METHODS
  We included all patients diagnosed as CCSK in the period between July 2007 and March 2012 at Children's Cancer Hospital, Egypt. Patients' demographics, clinical presentation, pathology, and management were reviewed. Follow up was continued until April 2013.
  
  
  RESULTS
  Twenty-five patients were identified in the defined time interval, accounting for 7% all renal tumors diagnosed at the hospital. Mean age was 36 months. Abdominal swelling and hematuria were the most common presentations. Stages I, II, III, IV, and V represented 9 (36%), 3 (12%), 8 (32%), 3 (12%), and 2 (8%), respectively. Twenty-four patients had radical nephrectomy either upfront or after neo-adjuvant chemotherapy. Surgery was followed by adjuvant chemotherapy. Abdominal radiotherapy was given for local stages II and III. Twenty-two patients reached complete remission, while one patient had stationary disease and two patients died due to progression and relapse. Overall survival was 88.5% and event-free survival was 87.8% at 45 months.
  
  
  CONCLUSIONS
  Although previous studies indicate poor prognosis of CCSK, our experience shows that those patients can be treated using extensive chemotherapy combined with proper local control.
authors.affiliation: Pediatric Oncology Department, Children's Cancer Hospital Egypt, Cairo, Egypt.
authors.forename: Wael
authors.initials: W
authors.lastname: Zekri
authors.forename: Ahmad Samir
authors.initials: AS
authors.lastname: Alfaar
authors.forename: Dina
authors.initials: D
authors.lastname: Yehia
authors.forename: Maged M
authors.initials: MM
authors.lastname: Elshafie
authors.forename: Mohamed Saad
authors.initials: MS
authors.lastname: Zaghloul
authors.forename: Naglaa
authors.initials: N
authors.lastname: El-Kinaai
authors.forename: Hala
authors.initials: H
authors.lastname: Taha
authors.forename: Amal
authors.initials: A
authors.lastname: Refaat
authors.forename: Alaa A
authors.initials: AA
authors.lastname: Younes
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D008175:Lung Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D008297:Male; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D009392:Nephrectomy; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D018227:Sarcoma, Clear Cell / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D015996:Survival Rate
keywords: clear cell sarcoma; including soft tissue sarcomas; non-rhabdoid; pediatric oncology; rare tumors; sarcomas; solid tumors