Subgroup-specific prognostic implications of TP53 mutation in medulloblastoma
TP53 mutations mark a very poor prognosis in SHH-subgroup medulloblastoma, with five-year survival around 40 percent, but have no effect in WNT tumours, so the mutation must be interpreted alongside the subgroup.
Overview
Analysis of 553 medulloblastomas for TP53 mutation by molecular subgroup in a discovery and validation cohort, finding TP53 mutations in 21 percent of SHH and 16 percent of WNT tumours but rarely in groups 3 and 4.
In SHH tumours, TP53 mutation was associated with five-year overall survival of 41 percent against 81 percent for wild-type, often with germline mutations (Li-Fraumeni syndrome) and chromothripsis, whereas WNT tumours with TP53 mutations retained excellent survival.
- SHH TP53-mutant: five-year overall survival 41 percent vs 81 percent for wild-type.
- WNT TP53-mutant: survival unaffected (90 percent).
SHH-activated, TP53-mutant medulloblastoma is a separate WHO entity treated as very high risk, and its diagnosis prompts germline testing of the child and family.
- Retrospective; treatment varied across cohorts.