Changes to This Summary (10/29/2014)
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Revised text to state that between 1975 and 2010, childhood cancer mortality decreased by more than 50% (cited Smith et al. as reference 3).
Added text to state that the incidence of embryonal tumors in children aged 1 to 9 years is fivefold to tenfold higher than is the incidence of embryonal tumors in adults (cited Smoll et al. as reference 18).
Revised text to state that children with medulloblastoma are usually diagnosed within 2 to 3 months of onset of symptoms and commonly present with relatively abrupt onset of headaches; vomiting; lethargy; unsteadiness, including truncal unsteadiness; some degree of nystagmus; and papilledema (cited 2014 Ramaswamy et al. as reference 20).
Revised text to state that cranial nerve findings are less common, except for unilateral or bilateral sixth nerve palsies, which are usually related to hydrocephalus.
Added Hereditary cancer predisposition syndromes associated with medulloblastoma as a new subsection.
Revised text to state that genomic analyses (including RNA gene expression and DNA methylation profiles, as well as DNA sequencing to identify mutations) on both fresh-frozen and formalin-fixed, paraffin-embedded sections have identified molecular subtypes of medulloblastoma (cited Schwalbe et al. as reference 63). Also added text to state that at recurrence, the subtype remains unchanged from the original molecular subtype at diagnosis (cited 2013 Ramaswamy et al. as reference 65).
Revised text to state that subtype 2 tumors are characterized by chromosome 9q deletions; desmoplastic/nodular histology; and mutations in sonic hedgehog (SHH) pathway genes, including PTCH1, PTCH2, SMO, SUFU, and GLI2.
Added text about the incidence and origin of subtype 2 tumors and the outcomes of patients with mutations present in SHH medulloblastoma (cited Zhukova et al., Shih et al., and Schwalbe et al. as references 25, 26, and 27, respectively).
Added text about the prognosis of patients with subtype 3 tumors.
Added text to state that loss of INI1 protein expression in the absence of rhabdoid cell morphology has been identified in a small subset of central nervous system primitive neuroectodermal tumors (cited Miller et al. as reference 32 and level of evidence 3iB).
Added Blaney et al. as reference 41 and level of evidence 2B.
This summary is written and maintained by the PDQ Pediatric Treatment Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ NCI's Comprehensive Cancer Database pages.