Approximately 70% of patients with neuroblastoma have metastatic disease at diagnosis. The prognosis for patients with neuroblastoma is related to their age at diagnosis, clinical stage of disease, site of the primary tumor, tumor histology, and, in patients older than 1 year, regional lymph node involvement. Biological prognostic variables are also used to help determine treatment (see below).[24,25,26,27] The 5-year overall survival for all infants and children with neuroblastoma has increased from 52% when diagnosed between 1973 and 1982, to 74% when diagnosed between 1999 and 2005; however, this single number can be misleading due to the extremely heterogeneous prognosis based on the neuroblastoma patients age, stage, and biology. (Refer to the Cellular Classification section of this summary for more information.)
The effect of age at diagnosis on 5-year survival is profound-age less than one year is associated with 90% survival, one to four years is 68%, five to nine 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.[24,29] 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.[32,33,34] Other modalities, such as local radiation therapy and the use of agents with confirmed activity, may improve the poor prognosis.[33,34] 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 LOH, and LOH for chromosome 1p.[27,29,36,37,38,39,40,41] 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.