a Institute for Personalized Cancer Therapy, The University of Texas MD Anderson Cancer Center, Houston, Texas; Nicklaus Children's Hospital, Pediatric Hematology and Oncology, Miami, Florida; and the Departments of Pediatrics, Bioinformatics and Computational Biology, and Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Metachronous neoplasms have rarely been reported in patients with neuroblastoma. This report presents the clinical case of a 23-month-old child who was diagnosed with an anaplastic medulloblastoma 5 months after completing treatment for stage IV neuroblastoma. The patient was treated with complete surgical resection and adjuvant chemoradiation followed by maintenance chemotherapy at an outside institution and came to our institution for further management. A pathologic diagnosis and review of both the suprarenal and posterior fossa masses were performed, as well as a genetic analysis of both cerebellar tumor tissue and blood using next-generation gene sequencing. At our institution, the patient was submitted to induction chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation and remains free of disease 2 years after completion of treatment. Genetic analysis revealed multiple somatic copy number variations with most deleted genes located in 2q37, a region which harbors genes involved in epigenetic regulation and tumor suppression. A homozygous deletion was found in the TSC2 gene, which is a clinically actionable gene, and patients with activating deletions in TSC2 can potentially be eligible for basket clinical trials with mTOR inhibitors. Germline single nucleotide variants were also identified in multiple genes involved in cancer (ALK, FGFR3, FLT3/4, HNF1A, NCOR1, and NOTCH2/3), cancer predisposition (TP53, TSC1, and BRCA1/2), and genes involved in DNA repair (MSH6, PMS2, POLE, and ATM). Metachronous neoplasms are rare and challenging to treat, hence genetic analysis and referral are needed to exclude hereditary cause. DNA sequencing of the tumor and germline can help identify alterations that increase predisposition or can be used to guide treatment decisions on recurrence and when standard options fail.
Correspondence: Wafik Zaky, MD, Department of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 87, Houston, TX 77030. Email: email@example.com