Stratified treatment of non-distant metastatic rhabdomyosarcoma in children: an analysis of its efficacy and prognostic factors

Abstract

Objective To assess the efficacy of stratified treatment of pediatric non-distant metastatic rhabdomyosarcoma (RMS). Methods A retrospective review was conducted in 129 pediatric patients with non-distant metastatic RMS between January 2005 and December 2016 at Shanghai Children′s Medical Center Affiliated to Shanghai Jiaotong University School of Medicine.According to their pathological types, TNM stages and postoperative pathologic staging, the 129 patients were grouped a low-risk group, an intermediate-risk group and a high-risk group.Multimodality therapies were applied to all patients including chemotherapy, surgery and radiotherapy.The overall survival (OS) and event-free survival (EFS) rates were analyzed by using the Kaplan-Meier method. Results Of 129 patients, 119 cases were included in this study.In 119 patients, the age of onset for the RMS ranged from 7 to 191 months, with the median onset age of 48 months.The median follow-up time was 40 months for event-free patients with RMS, and 36 months for all the 119 patients.The 5-year OS and EFS for all patients were (92.1±2.9)% and (76.5±4.4)%, respectively.While the 5-year EFS for patients in the low-risk group, intermediate-risk group and high-risk group were all above 70%, and the difference among the three groups was not statistically significant (χ2=2.679, P=0.262). A subsequent univariate analysis revealed that the onset age for RMS (≤1 year old or≥10 years old), TNM stage and postoperative pathologic stage were important predictors of EFS with statistical significance (all P 0.05). The 5-year EFS of RMS patients with Forkhead Box Protein O1(FOXO1)-positive was significantly lower than that of FOXO1-negative patients [(56.3%±14.8)% vs.(83.3±15.2)%], and the difference was statistically significant (χ2=4.588, P=0.028). Conclusions It is important that the stratification treatment should be strictly implemented on RMS patients.First, further improvement is necessary for the treatment of patients in the low-risk group due to their poorer prognosis compared to that of their intermediate-risk counterparts, for whom one feasible option is to reduce the dose of chemotherapy drug.Furthermore, FOXO1 can be used as an indicator for poor prognosis, where stratified treatment is necessary for pediatric patients with RMS. Key words: Rhabdomyosarcoma; Stratification treatment; Prognosis; Child