Iccc Iv Sympathetic Nervous System Tumors

Incidence ♦ In the US, approximately 700 children and adolescents younger than 20 years of age are diagnosed with tumors of the sympathetic nervous system each year, of which approximately 650 are neuroblastomas. ♦ Sympathetic nervous system tumors accounted for 7.8% of all cancers among children younger than 15 years of age. ♦ Over 97% of sympathetic nervous system tumors are neuroblastomas, embryonal malignancies of the sympathetic nervous system that occur almost exclusively in infants and very young children. ♦ Regardless of age, neuroblastomas most commonly occurred in the adrenal gland. Mediastinal tumors were more frequent in infants than in older children, while the opposite age pattern was observed for CNS tumors (Figure IV.1). ♦ The average age-adjusted annual incidence rate for all sympathetic nervous system cancers was 9.5 per million children. ♦ The occurrence of sympathetic nervous system malignancies was strongly age-dependent (Figure IV.2). For neuroblastomas alone, the incidence rate for both sexes combined during the second year of life (29 per million) was less than half that of infancy (64 per million). ♦ Neuroblastomas were by far the most common cancer of infancy, with an incidence rate almost double that of leukemia, the next most common malignancy that occurred during the first year of life. ♦ Sixteen percent of infant neuroblastomas were diagnosed during the first month following birth and 41% were diagnosed during the first 3 months of life (Figure IV.3). ♦ Over the 21-year observation period, there was little indication of an increase in the overall incidence of sympathetic nervous system malignancies (Figure IV.4). The estimated annual percent change in age-adjusted incidence rates was 0.4%.