Outcomes of Infant Medulloblastoma Treated With Standard-Dose Chemotherapy-A Single-Institution Experience From a Low-Middle-Income Country.

Background: Infant medulloblastoma (iMBL) is predominantly desmoplastic nodular (DN) or medulloblastoma with extensive nodularity (MBEN) histology, sonic hedgehog (SHH) driven. Intensified chemotherapy (intraventricular chemotherapy or high-dose chemotherapy with autologous stem cell rescue) is recommended to compensate for the omission of radiation. This study aims to analyze the outcomes of iMBL treated without treatment intensification.

Methods: This retrospective study was performed on 28 patients with iMBL (children with medulloblastoma <3 years at diagnosis or 3-4 years with DN/MBEN histology) treated between January 2004 and April 2024 in a tertiary care institute in southern India.

Results: The median age at diagnosis and duration of symptoms were 24.5 months and 1 month, respectively. Vomiting (82%) and ataxia (71.4%) were the common presentations. Ventriculoperitoneal shunt or endoscopic third ventriculostomy was done in 57% of patients. Twenty-four patients (∼86%) underwent gross/near-total resection. The most common surgical complication was cerebellar mutism (n = 6, 21%). Half of the cohort had nonmetastatic disease. Sixteen patients had DN/MBEN histology. Only 68% (n = 19) opted to continue postoperative treatment. Chemotherapy protocols used were baby SFOP, HIT SKK, and modified Packer. One fourth (n = 7) received radiation (DN/MBEN = 3; other histology = 4) as a part of their initial treatment. There was no treatment-related mortality. The 5-year event-free survival (EFS) of patients who received postoperative chemotherapy ± RT was 70% (those with DN/MBEN were 82.5% and non-DN/MBEN were 35.7%). The 5-year EFS of patients with DN/MBEN histology who received only chemotherapy (n = 9) was 88.9%.

Conclusions: Managing medulloblastoma in infants is challenging in LMIC, as a significant proportion of families opt against postoperative treatment. Although traditionally considered high risk, good survival can be achieved with non-intensified therapy without an increase in treatment-related mortality, especially in patients with DN/MBEN histology.