Epidemiology of Central Nervous System Tumors Occurring During Infancy

Incidence and Prevalence

• Incidence of 0.06 to 0.3/100,000/year: CNS tumors in infants account for approximately 13% of all cancers by incidence or 30 per million population (5). CNS tumors in infants account for 1.4 – 8.5% of all childhood CNS tumors (6). Taking an incidence of 4.03/100,000 anticipates a population incidence of 0.06–0.3/100,000 infantile CNS tumors per annum (10).
• True incidence masked by lack of information about stillborns or aborted fetuses: The true incidence of disease in the infant population may be masked by missed statistics from stillborn or aborted fetuses. Historical series suggest that the predominant tumor in this group is teratoma (6).
• Teratomas: Teratomas are often noted as a conatal tumor, with recognition decreasing after the first few months of life (4).
• Neuroblastomas: Neuroblastomas are the commonest extracranial tumor in children and the most common cause of spinal cord/nerve root compression in infants (8,18).  28% of all infant cancer cases in the SEER data (U.S. National Cancer Institute Surveillance Epidemiology and End Results) were of neuroblastoma with an incidence of 65 per million infants (5).
• PNETs: Other PNETs and medulloblastomas are reported commonly in the infantile literature, but may be over-represented in this group by prior inclusion of the AT/RT group before recognition as a distinct entity.
• AT/RTs: The incidence of AT/RTs is 1.38 per 1,000,000 person-years in children. Peak incidence is in the age group from birth to 2 years.
• Desmoplastic infantile gangliogliomas: These are very rare tumors occurring almost solely in infants, usually before the age of 4 months.
• Medulloepitheliomas: These are rare, primitive tumors of infants/young children.

Age Distribution

• Neuroblastomas: More than 50% of neuroblastomas occur in children under the age of 2 years.
• AT/RTs: AT/RT remains a significant tumor of infancy. Rorke et al. (13) reported a series of 52 patients in which the median age at diagnosis was 16.5 months (mean 29 months).
• Desmoplastic infantile gangliogliomas: One series reported that patients with desmoplastic infantile gangliogliomas presented between 2 and 24 months of age (mean 6 months; median 4 months) (23).
• Medulloepitheliomas: The median age at presentation is 17 months (14).

Sex Predilection

• None proven but possible trend toward female: Overall, there is no statistically proven sex preference for tumors in the CNS of infants.   Several papers, however, describe a tendency toward female preponderance, especially with astrocytic tumors and PNETs (6, 21).
• Neuroblastomas: Male:female ratio is 1.3:1 (7).

AT/RTs: Male:female ratio is 3:2 (13).

• Medulloepitheliomas: No sex predilection.

Geographic Distribution

• There is no geographical variance.

Risk Factors

• There are no known risk factors.

Relationships to Other Disease States and Syndromes

See molecular genetic associations in the next section.