Table 1.

Summary of clinical histories.

	Medulloblastoma	Germline studies	Age at Dx	Treatment	2nd cancer	Treatment	3rd cancer	Treatment	Outcome, time after MB, age
1	Desmoplastic/nodular MB (standard risk) Pathology: Non-amplified MCYN TP53 wildtype SHH-MB	De novo TP53 pathologic variant from buccal swab Parents tested	8y	Packer’s protocol (Lomustine, vincristine, cisplatin) CSI (23.4Gy) + tumor bed boost (30.6Gy) Total 54 Gys	Myelodysplastic neoplasm with biallelic TP53 inactivation, germline TP53 LP variant, post cytotoxic therapy (Dicentric chromosome 5, 17) MB: no evidence of recurrence 17 months from MB	Azacitidine (2 courses) Haploidentical HSCT 4 courses Conditioning regimen:  • Alemtuzumab 0.6mg/kg  • Fludarabine 150mg/m2  • Thiotepa 10mg/kg  • Melphalan 140mg/m2	T-LBL, stage III MB: no evidence of recurrence 45 months from MB	Methotrexate, asparaginase, vincristine, daunorubicin	Died from T-LBL (3rd cancer) 48 months from diagnosis 12y
2	Focal anaplastic features Pathology: Non-amplified MYCN TP53 mutant SHH-MB	TP53 pathologic variant from EDTA blood Parents not tested	9y	Packer’s protocol (Lomustine, vincristine, cisplatin) Withheld at cycle 7 due to PRES CSI (36Gy cranial + 36Gy spinal)	Myelodysplastic neoplasm with biallelic TP53 inactivation, germline TP53 LP variant, post cytotoxic therapy (5q loss, monosomy 7, trisomy 8, 17p loss) MB: no evidence of recurrence 33 months from MB	Double cord blood transplantation Conditioning regimen:  • Cyclophosphamide 120mg/kg  • Busulfan dose 12.8 mg/kg  • Antithymocyte globulin 5mg/kg  • Melphalan 140mg/m2			Died from complication of HSCT 43 months from diagnosis 13y
3	Classic medulloblastoma Pathology: Non-amplified MYCN Group 3 46 months: Recurrent anaplastic medulloblastoma Variant allele 47.8%, for MUTYH protein, unknown significance	TP53 mutation not reported from EDTA blood Parents not tested	5y	1. HKPHOSG PNET-CNS-2000 protocol Cisplatin, vincristine, lomustine Proton Stereotactic Body Radiation Therapy (23.4Gy) and tumor bed boost (1-1.5cm margin). Total 54 Gys 2. MEMMAT protocol Bevacizumab, thalidomide, celecoxib, fenofibrate (oral) Etoposide, cyclophosphamide (systemic) Etoposide, cytarabine (intraventricular) SBRT of recurrent lesions in left frontal region (54Gy) CAR-T cell therapy anti-GD2	Acute myeloid leukemia, myelodysplasia-related, post cytotoxic therapy (Monosomy 7) MB: disease progression with BM involvement 65 months from MB (18 months from relapse)	Azacitidine, venetoclax (1 course)			Died from complications of medulloblastoma and MDS 69 months from diagnosis 11y