Neuroblastoma Treatment (PDQ®): Treatment - Health Professional Information [NCI] - General Information
The diagnosis of neuroblastoma requires the involvement of pathologists who are familiar with childhood tumors. Some neuroblastomas cannot be differentiated, via conventional light microscopy, from other small round blue cell tumors of childhood, such as lymphomas, primitive neuroectodermal tumors, and rhabdomyosarcomas. Evidence for sympathetic neuronal differentiation may be demonstrated by immunohistochemistry, electron microscopy, or by finding elevated levels of serum catecholamines (e.g., dopamine and norepinephrine) or urine catecholamine metabolites, such as vanillylmandelic acid (VMA) or homovanillic acid (HVA). The minimum criterion for a diagnosis of neuroblastoma, as has been established by international agreement, is that it must be based on one of the following:
- An unequivocal pathologic diagnosis made from tumor tissue by light microscopy (with or without immunohistology, electron microscopy, or increased levels of serum catecholamines or urinary catecholamine metabolites).
- The combination of bone marrow aspirate or trephine biopsy containing unequivocal tumor cells (e.g., syncytia or immunocytologically-positive clumps of cells) and increased levels of serum catecholamines or urinary catecholamine metabolites, as described above.
However, primary tumor tissue is often needed to obtain all the biological data that may be used to determine treatment in current COG clinical trials. There is an absolute requirement for tissue biopsy to determine the International Neuroblastoma Pathology Classification (INPC) (see Cellular Classification section for more information). The INPC was used to determine treatment in the COG risk assignment schema for prior COG studies in patients with stage 2, 3, and 4S tumors. In the risk/treatment group assignment schema for the current COG studies, INPC is used to determine treatment for stage 3 and 4S patients as well as for stage 4 patients aged 18 months or younger. Additionally, a significant number of tumor cells are needed to determine MYCN copy number DNA index and 11q and 1p loss of heterozygosity. For older stage 4 patients, bone marrow with extensive tumor involvement combined with elevated catecholamine metabolites is adequate for study entry.
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).[25,26,27,28] The 5-year overall survival for all infants and children with neuroblastoma has increased from 46% when diagnosed between 1974 and 1989, to 71% when diagnosed between 1999 and 2005; however, this single number can be misleading due to the extremely heterogeneous prognosis based on the neuroblastoma patient's age, stage, and biology. (Refer to the Cellular Classification section of this summary for more information.)