title: Management and follow-up of Ewing sarcoma patients with isolated lung metastases.
abstract: BACKGROUND
  Ewing sarcoma (ES) is the second most common pediatric malignant bone tumor with a wide spectrum of clinical presentations. Although metastatic disease to the lungs is often the cause of death, isolated lung metastases at diagnosis are not frequent. The specific role of chemotherapy, surgery, and lung radiation has not been clearly defined. We investigated prognostic factors and the impact of the different treatment modalities in a cohort of patients with ES with isolated lung metastases.
  
  
  METHODS
  Thirty-eight patients with ES and isolated lung metastases were treated using modern multimodal therapy during the period 2000-2014. According to the imaging characteristics of lung nodules patients were allocated into one of four treatment groups: "0" without nodules, "1" one solitary nodule of <0.5cm or several nodules of <0.3cm, "2" solitary nodule of 0.5-1cm or multiple nodules of 0.3-0.5cm, "3" one pulmonary/pleural nodule of >1cm, or more than one nodule of >0.5cm. Factors predictive of outcome were analyzed. Overall survival was estimated by Kaplan-Meier methods and compared using long-rank test and Cox models.
  
  
  RESULTS
  Treatment of the lung metastases was performed in 23 cases (60.5%): twenty patients underwent lung surgery, 6 of them received additional postoperative whole lung radiation; three patients received lung radiation only. Malignant cells were found in all lung nodules of patients from group "3", in 5 (62.5%) patients from group "2", and none of the group "1". There was a correlation between histological response of the primary tumor and outcome. Three-year estimates of EFS and OS were 45.19% and 60.7%, respectively. Patients with good response measured by chest CT had significantly better EFS than patients with poor response (81% vs. 27.66%, respectively, p=0.006).
  
  
  CONCLUSIONS
  Metastatectomy may have a role in the treatment of highly selected patients with ES and isolated lung metastases depending on the histologic response to therapy. Further studies are needed to better define the use of surgery and the response-adapted criteria in the upfront management of this population.
authors.affiliation: Department of Surgical Oncology for Children and Youth, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland. Electronic address: anna.raciborska@hoga.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Raciborska
authors.affiliation: Department of Surgical Oncology for Children and Youth, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Bilska
authors.affiliation: Department of Surgical Oncology for Children and Youth, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rychłowska-Pruszyńska
authors.affiliation: Department of Radiology, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Duczkowski
authors.affiliation: Department of Radiology, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Duczkowska
authors.affiliation: Department of Pediatric Hematology, Oncology and Bone Marrow Transplantation, Medical University of Lublin, A. Gebali 6 str., 20-093 Lublin, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Drabko
authors.affiliation: Department and Clinic of Pediatric Oncology, Hematology and Bone Marrow Transplantation, Wroclaw Medical University, Bujwida 44 str., 50-368 Wroclaw, Poland.
authors.forename: Radosław
authors.initials: R
authors.lastname: Chaber
authors.affiliation: Unit of Pediatric Oncology, Hematology and Chemotherapy, Medical University of Silesia, Medyków 16 str., 40-752 Katowice, Poland.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Sobol
authors.affiliation: Department of Oncology and Hematology, University Children's Hospital of Cracow, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Wyrobek
authors.affiliation: Department of Pathology, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Michalak
authors.affiliation: Pediatric Oncology, Dana-Farber Cancer Institute and Children's Hospital, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodriguez-Galindo
authors.affiliation: Department of Surgical Oncology for Children and Youth, Institute of Mother and Child, Kasprzaka 17a str., 01-211 Warsaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Wożniak
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000473:pathology*; D002648:Child; D003131:Combined Modality Therapy / Q000379:methods; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary*; D008297:Male; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000556:secondary* / Q000628:therapy
keywords: Ewing sarcoma; Lung metastases; Radiation; Survival; Thoracotomy