Comparison of mediastinal and non-mediastinal neuroblastoma and ganglioneuroblastoma associated with opsoclonus-myoclonus syndrome: a systematic review and meta-analysis

BACKGROUND: Neuroblastoma is the most common malignancy in children younger than seven years of age and is the most frequent extracranial solid tumor that occurs in childhood. While opsoclonus–myoclonus syndrome (OMS), a paraneoplastic neurologic syndrome, affects 2–3% of children with neuroblastoma, and the percentage of mediastinal localization of the tumor is 49%. The objective of this study was to identify and characterize features of the OMS syndrome and treatments of mediastinal and non-mediastinal neuroblastoma associated with OMS. METHODS: A systematic review of the literature was performed using PubMed, Medline, Web of Science, Embase and Cochrane. The search has no limit on date with the last search done on Dec 31, 2020. There is no publication restrictions or study design filters applied in the search. RESULTS: Fifty-five out of 242 papers were identified and met our study eligibility. There were 77 cases found (28 cases had Mediastinal neuroblastoma, and 49 cases had non-mediastinal neuroblastoma). Data from trials showed that cases with mediastinal neuroblastoma who seemed to have undergone less treatment for OMS [rate ratio (RR) 0.41 (95% CI: 0.22–0.76)] had resulted in decreasing persistent neurologic symptoms [RR 0.31 (95% CI: 0.10–0.96)]. CONCLUSIONS: Children who have OMS and mediastinal neuroblastoma may be associated with more favorable clinical and biological characteristics and better outcomes than children who have OMS and non-mediastinal neuroblastoma, and they are more likely to present with a single neurological symptom at first. The OMS in mediastinal neuroblastoma might also be treated effectively through resection of the tumor followed by appropriate radiotherapy and chemotherapy, and no long-term treatments of OMS is indicated.