The effect of age at diagnosis on 5-year survival is profound—age younger than 1 year is associated with 90% survival, 1 to 4 years is 68%, 5 to 9 years is 52%, and 10 to 14 years is 66%. Children of any age with localized neuroblastoma and infants aged 18 months and younger with advanced disease and favorable disease characteristics have a high likelihood of long-term, disease-free survival. The prognosis of fetal and neonatal neuroblastoma are similar to that of older infants with neuroblastoma and similar biological features. Older children with advanced-stage disease, however, have a significantly decreased chance for cure, despite intensive therapy. For children aged 18 months and older with stage 4 neuroblastoma, who receive aggressive treatment with surgery and radiation therapy to the primary tumor mass, as well as aggressive chemotherapy with hematopoietic stem cell rescue followed by cis -retinoic acid, long-term survival is approximately 30% to 50%.
The clinical characteristics of neuroblastoma in adolescents are similar to those observed in children. The only exception is that bone marrow involvement occurs less frequently, and there is a greater frequency of metastases in unusual sites such as lung or brain. Neuroblastoma has a worse long-term prognosis in an adolescent or adult compared to a child, regardless of stage or site and, in many cases, a more prolonged course when treated with standard doses of chemotherapy. Aggressive chemotherapy and surgery have been shown to achieve a minimal disease state in more than 50% of these patients.[33,34,35] Other modalities, such as local radiation therapy and the use of agents with confirmed activity, may improve the poor prognosis.[34,35] However, the overall prognosis for older patients is dismal.
A number of biologic variables have been studied in children with this tumor. Treatment decisions are usually based on important factors such as the INPC (refer to the Cellular Classification section of this summary for information about the INPC system), ploidy, amplification of the MYCN oncogene within tumor tissue, unbalanced 11q loss of heterozygosity, and loss of heterozygosity for chromosome 1p.[28,37,38,39,40,41,42,43] In the future, MYCN amplification, 11q23 alleles, and ploidy (along with standardized procedures for evaluation) are expected to be the standard factors used for evaluation of treatment programs, as established by the International Consensus for Neuroblastoma Molecular Diagnostics. An open biopsy is often needed to obtain adequate tissue for determination of these biological characteristics.
Many biological characteristics of tumors are not currently used in determining therapy; however, as clinical research matures, these characteristics may be found useful as therapeutic targets or as clinically important prognostic factors. Amplification of the MYCN gene is associated not only with deletion of chromosome 1p, but also gain of the long arm of chromosome 17 (17q), the latter of which independently predicts a poor prognosis. In contrast to MYCN gene amplification, the degree of expression of the MYCN gene in the tumor does not predict prognosis. However, high overall MYCN-dependent gene expression and low expression of sympathetic neuron late differentiation genes both predict a poor outcome of neuroblastomas otherwise considered to be at low or intermediate risk of recurrence.ATRX is involved in epigenetic gene silencing and telomere length. ATRX mutation without MYCN amplification is associated with age at diagnosis in adolescents and young adults with metastatic neuroblastoma.