Treatment and revaccination of children with paraneoplastic opsoclonus-myoclonus-ataxia syndrome and neuroblastoma: The Memorial Sloan Kettering experience.

Objective: To review the treatment and revaccination of neuroblastoma-associated opsoclonus-myoclonus-ataxia syndrome (OMAS) patients at Memorial Sloan Kettering Cancer Center (MSK).

Procedure: Institutional Review Board approval was obtained for this retrospective study of patients with neuroblastoma-associated OMAS followed at MSK from 2000 to 2016.

Results: Fourteen patients (nine female) were 9-21 (median 17) months old at diagnosis of neuroblastoma and OMAS syndrome. They had stage 1 (n = 12), stage 2B, or intermediate-risk stage 4. Tumor histology was favorable in 11 patients, unfavorable in two, and unknown in one patient. No patient had amplified MYCN. All patients underwent tumor resection at diagnosis. Anti-neuroblastoma treatment was limited to chemotherapy in one patient. Overall survival is 100% at 3-16 (median 10) years. For OMAS, 13 patients received intravenous immune globulin (IVIg), adrenocorticotropic hormone (ACTH), and rituximab, and one received ACTH and IVIg. Seven patients experienced OMAS relapse. For these relapses, five patients received low-dose cyclophosphamide and two received rituximab. The mean total OMAS treatment was 20-96 (median 48) months. Seven patients started rituximab ≤3 months from diagnosis and did not relapse. The other six experienced OMAS relapse. To date, six patients have been revaccinated at a minimum of 2 years after completion of OMAS therapy without OMAS recurrence.

Conclusions: Patients with neuroblastoma-associated OMAS had excellent overall survival. Early initiation of rituximab, IVIg, and ACTH may reduce risks of OMAS relapse. Revaccination can be resumed without exacerbation of OMAS. Further investigation with a larger cohort of patients is needed.