Radiotherapy Of Children’s Rhabdomyosarcoma

PartⅠ Retrospective study of prognostic factors in patients with rhabdomyosarcoma:experience at a mono-institutionBackground:Rhabdomyosarcoma(RMS)is a rare and highly aggressive form of soft-tissue tumor that affects both children and adolescents.Despite the high rates of morbidity and mortality,data on the epidemiology of RMS in Asia and clinical features of patients with RMS are limited.This study aimed to investigate the epidemiology,clinical features,treatments,and prognosis of patients with different subtypes of RMS.Methods:The clinical characteristics of 137 patients with a pathological diagnosis of RMS were retrospectively analyzed.Two major subtypes of RMS,embryonal RMS(ERMS)and alveolar RMS(ARMS),were compared and analyzed in terms of clinical features such as the presence of fusion genes,tumor sites,local extension,nodal involvement,metastases,treatment,and prognosis.Results:Of all 137 patients,the median age at diagnosis was 4.9 years[range 2.4-8.9],with a male-female sex ratio of 1.25:1.The perimeningeal location in the head and neck area was the most common primary site of the tumor.Among 131 patients diagnosed with ERMS or ARMS,nodal involvement,metastases,and the status of the PAX3-FOXO1 fusion gene were more commonly associated with patients with ARMS.Patients with ERMS presented with relatively larger tumor size and better therapeutic outcomes.The estimated 2-year event-free survival(EFS)and overall survival(OS)rates were 47.1%and 71.9%,respectively.In univariate analysis,histology,regional lymph node involvement,metastases,clinical group,TNM staging,and risk stratification were significantly correlated with OS.Only metastases emerged as independent prognostic factors for OS.Conclusions:Patients with ARMS presented with a smaller tumor size at the primary site compared to those with ERMS.Moreover,ARMS was associated with a more aggressive phenotype,resulting in a greater possibility for nodal involvement,distal metastases,and worse therapeutic outcomes.Distal metastases were identified as an independent prognostic factor for OS.Part Ⅱ Prognostic models for predicting overall and cancer-specific survival in postradiotherapy patients with rhabdomyosarcoma:Nomograms construction and validationBackground:Rhabdomyosarcoma(RMS)is a rare malignant tumor.The last decades saw the improvement in the overall survival of patients with RMS.Radiotherapy,as a main part of the treatment modality,has led to increased survival rate and improved life quality.Accordingly,the overall survival rate and cancer-specific survival rate after treatment of radiotherapy have aroused an attention among physicians and patients.This study aims to investigate the prognostic factors for RMS patients who have received radiotherapy,providing a useful clinical tool for radiotherapists.Methods:The characteristic information of patients with RMS after radiotherapy were collected from surveillance,epidemiology,and end results(SEER)database and further adopted for survival analysis.Nomograms of short-term survival probability were established and validated by both internal and external cohorts.Results:The 1-,2-and 3-year overall survival rates of patients with RMS after radiotherapy were 89.6%,76.6%,and 66.4%,respectively.The 1-,2-,3-year cancer-specific survival rates were 91.2%,79.7%,69.8%,respectively.Age larger than 15 years,alveolar subtype,other subtype,tumor larger than 10 cm,regional extension,distant metastasis,and complete surgical removal remained significant prognostic factors for overall survival and cancer-specific survival.Nomograms predicting overall survival and cancer-specific survival after radiotherapy were established according to the multivariate analysis.Calibration plots for 3-year survival prediction showed fair agreement between predicted and actual survival for the internal and external data sets.The C-indexes and all the AUCs indicated a relatively good discrimination ability of the nomograms established.Conclusions:This study identifies the prognostic factors of postradiotherapy patients with RMS.The models we proposed could realize individualized prediction of short-term clinical outcomes.Part Ⅲ Second Malignant Neoplasms in patients With RhabdomyosarcomaObjective:Rhabdomyosarcoma(RMS)is a rare malignant tumor.The main treatment modality is comprehensive with chemotherapy,radiotherapy,and surgery.With the advancement in recent decades,patient survival has been prolonged,and long-term complications are attracting increasing attention among both physicians and patients.This study aimed to present the survival of patients with RMS and analyze the risk factors for the development of a second malignant neoplasm(SMN).Methods:The Surveillance,Epidemiology,and End Results(SEER)Program 18 registry database from 1973 to 2015 of the National Cancer Institute of the United States was used for the survival analysis,and the SEER 9 for the SMN analysis.Results:The 5-,10-,and 20-year overall survival rates of the patients with RMS were 45%,43%,and 33%,respectively.The risk of SMN was significantly higher in patients with RMS compared to the general population(SIR=1.95,95%CI:1.442.57,p<0.001).The risk of developing SMN was increased in multiple locations,including the bones and joints(SIR=35.25)soft tissues including the heart(SIR=22.5),breasts(SIR=2.10),male genital organs(SIR=118.14),urinary system(SIR=2.36),brain(SIR=9.21),and all nervous system organs(SIR=8.59).The multivariate analysis indicated that RMS in the limbs and earlier diagnosis time were independent risk factors for the development of SMN.Patients with head and neck(OR=0.546,95%CI:0.313-0.952,p=0.033)and trunk RMS(OR=0.322,95%CI:0.184-0.564.p<0.001)and a later diagnosis time were less likely to develop SMN(OR=0.496,95%CI:0.421-0.585,p<0.001).Conclusion:This study describes the risk factors associated with the development of SMN in patients with RMS,which is helpful for the personalized screening of high-risk patients with RMS.