An analysis of the diagnosis, clinical characteristics, treatment, and survival outcomes of 36 extracranial malignant rhabdoid tumor patients.

Abstract

Background\nExtracranial malignant Rhabdoid tumors (eMRTs) are rare but aggressive lesions in young children. This work aimed to review and analyze the diagnosis, clinical characteristics, treatment, and survival of eMRTs so as to summarize experience for future therapy.\n\n\nMethods\nA total of 36 eMRT cases were treated between January 2008 and August 2019 according to Shanghai Children s Medical Center (SCMC) multimodal protocol of mixed surgery, radiation and chemotherapy involving vincristine, carboplatin, doxorubicin, etoposide, cyclophosphamide and ifosfamide. We collected information including: age at diagnosis, tumor location, disease stage, therapy, outcomes, etc. Overall survival (OS) and event free survival (EFS) were calculated and risk factors for survival were analyzed.\n\n\nResults\nThe patients had a median age of 1.80 years at diagnosis (range, 1.4 m-13.42 years), and were followed up for 9.17 months in median (range, 4 d-11.14 y). A total of 16 patients achieved complete remission (CR), and 7 survived without reoccurrence till December 2019. The 3-year EFS was 17.4% (95% CI: 11.0-23.8%) with a 3-year OS of 23.4% (95% CI: 15.8-31.0%). Recurrence was found only in children younger than the median age (1.80 y). Localized staging (Log Rank P=0.039 for OS and P=0.021) and older age (Log Rank P=0.016 for OS and P=0.002 for EFS) were associated with improved outcome. Younger age (Cox regression, OS, OR =2.610, 95% CI: 1.147-5.937, P=0.022; EFS, OR =3.401, 95% CI: 1.495-7.752, P=0.004) were independent risk factors for death and recurrence.\n\n\nConclusions\nThose eMRTs treated according to SCMC protocol turned out to have poor outcomes. Higher staging at diagnosis and reoccurrence in younger patients remain major threats to the prognosis.