title: Clinical characteristics and prognosis of childhood rhabdomyosarcoma: a ten-year retrospective multicenter study.
abstract: OBJECTIVE
  Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma in children. We have retrospectively explored the treatment results of childhood RMS and identified prognostic factors in multicenter in China, in order to lay the foundation for further multicenter study.
  
  
  METHODS
  This retrospective study was carried out analyzing the medical records of 161 patients with the pathological diagnosis of RMS from January, 2001 to February, 2014 at 5 large cancer centers in China. The data was reviewed clinico-epidemiological factors. Age, gender, histology type, primary site, tumor size, intergroup rhabdomyosarcoma study (IRS) group and results of treatments were evaluated. Patients were followed up to Dec 31, 2014.
  
  
  RESULTS
  The median age of our patients was 51 months. 10.5% of our patients were infants. The genitourinary system was the most common primary site of tumor (43.5%). The proportion of primary site of head and neck except parameningeal, at 28.2% (42 cases), while the proportion of parameningeal region was 4.6% (7 cases). The histological findings were as follows: 130 cases (80.7%) with embryonal, 19 cases (11.9%) with alveolar and 5 cases (3.1%) with botryoid type. According to the classification system of the IRS group, 1 case (0.6%) was group I, 54 cases (33.5%) were group II, 46 cases (28.6%) were group III and 60 cases (37.3 %) were group IV. 149 patients were treated and followed-up regularly, Patients in Beijing children's hospital (n=95) were enrolled in IRS-II/COG-D9803, D9802 protocols. while the other patients (n=54) started on treatment according to Chinese Anti-cancer Association protocol. There were median time of 51 months for following up, 60 occurred event. The ten-year event free survival rate was 53.4±5.1%, overall survival was 65.3±6.3%. The relations between outcome and age (0.046), primary site (0.022), pathologic subtype (0.013), tumor size (0.008) and IRS group (P=0.000) were associated significantly with event free survival. Among the variables, age (P=0.028) and IRS group (P=0.000) were associated significantly with overall survival. Multivariate analysis showed that overall survival for RMS was dependent on IRS group (P=0.026).
  
  
  CONCLUSIONS
  The epidemiological characteristics of our patients are quite similarly to the worldwide data. Except for the higher prevalence of group IV in our patients and the higher percentage of patients with primary tumor site in the genitourinary system, this study showed that overall survival for RMS is depended on disease group.
authors.affiliation: Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University Beijing 100045, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Pediatrics, Beijing Tong Ren Hospital Beijing 100730, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Huang
authors.affiliation: Peking University First Hospital Beijing 100034, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Beijing Shijitan Hospital Beijing 100038, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Sun
authors.affiliation: Wuhan Children's Hospital Wuhan 430000, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Xiong
authors.affiliation: Beijing Tong Ren Hospital China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University Beijing 100045, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Jin
authors.affiliation: Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University Beijing 100045, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Beijing Children's Hospital, Capital Medical University China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.affiliation: Beijing Children's Hospital, Capital Medical University China.
authors.forename: Huanmin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Beijing Children's Hospital, Capital Medical University China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Beijing Children's Hospital, Capital Medical University China.
authors.forename: Ning
authors.initials: N
authors.lastname: Sun
authors.affiliation: Beijing Children's Hospital, Capital Medical University China.
authors.forename: Lejian
authors.initials: L
authors.lastname: He
authors.affiliation: Shanghai Childrens' Medical Center China.
authors.forename: Jingyan
authors.initials: J
authors.lastname: Tang
keywords: Childhood RMS; China; multicenter