Incidence and Outcome of Pediatric Malignant Neuroendocrine Tumors

Purpose: Malignant neuroendocrine tumors (NET) are rare solid tumors infrequently seen in children. We sought to examine current incidence trends and outcomes for children with NET. Methods: The SEER registry was examined for patients between birth and 19 years of age between 1973 and 2004. Results: Overall, 481 patients were identified with malignant NET. Females outnumbered males 53 vs 47% for an age-population adjusted incidence of 0.995 and 0.504 per 100,000, respectively. Adolescents (15-19 years) comprised 55% (n=266) of the cohort, while 9.6% (n=61) were less than 10 years old. The majority of patients were white (81%), non-Hispanic (83%), who had the highest and increasing incidence (0.751/100,000 population and APC=0.842, p<0.05). Tumors were classified as malignant carcinoid (n=189, 39.3%), neural (n=127, 26.4%), medullary thyroid carcinoma (n=88, 18.3%), neuroendocrine carcinoma (n=50, 10.4%), pheochromocytoma (n=17, 3.5%), and paraganglioma (n=7, 1.5%). Only 15.6% of tumors were in the appendix. Over 60% (n=232) of patients had localized disease, while 13.5% (n=52) presented with distant metastasis. Children less than 5 years of age had worse 5-year survival (< 50% vs>76% if older, p=0.009). Blacks had lower 5-year survival compared to whites (61% vs 81%, p=0.001). Favorable tumor locations included appendix, lung, and thyroid (> 95% 5 year survival), whereas soft tissue, and ovary location were associated with poor survival (p<0.001). Distant metastasis, radiation therapy, and no surgery were all associated with less than 55% 5-year survival (vs>80% 5-year survival for localized disease, no radiation, and surgery, p<0.001). Conclusions: Pediatric NET are seen rarely in children but whites have the highest incidence which significantly increased for this group throughout the study period. Black children and those less than 5 years of age had lower survival.