Neuroblastoma, which is derived from the sympathetic nervous system, is the second most common pediatric solid malignant
tumor. This pediatric
tumor has a heterogeneous course, ranging from
spontaneous regression to inexorable progression and death, depending on the biological features of the
tumor. Identification of risk groups on the basis of clinical and molecular prognostic variables has allowed tailor-made
therapy to improve outcomes and minimize the risk of deleterious consequences of
therapy. In Japan, current therapeutic stratification of patients with
neuroblastoma is based on risk assessment according to combinations of age,
tumor stage, MYCN status,
DNA ploidy status, and histopathology; however, unfavorable
neuroblastoma is still one of the most difficult
tumors to cure, with only 40 % long-term survival despite intensive multimodal
therapy. Further refined therapeutic stratification based on newly identified prognostic factors will be required to improve the outcome of patients with unfavorable
neuroblastoma and reduce the side effects of
therapies for patients with favorable
neuroblastoma. In the present review, we describe recent topics on the molecular and genetic bases of
neuroblastoma; we hope this review will be helpful for understanding the mechanism of
neuroblastoma tumorigenesis and aggressiveness and for developing a new therapeutic stratification and new protocols for
neuroblastoma treatments.