Age at diagnosis
The effect of age at diagnosis on 5-year survival is profound. The 5-year survival stratified by age is as follows:
- Age younger than 1 year – 90%.
- Age 1 to 4 years – 68%.
- Age 5 to 9 years – 52%.
- Age 10 to 14 years – 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.
Adolescents and young adults
Neuroblastoma has a worse long-term prognosis in an adolescent older than 12 years or in an adult compared with 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.[32,54,55] Other modalities, such as local radiation therapy and the use of agents with confirmed activity, may improve the poor prognosis for adolescents and adults.[54,55]
Clinical stage of disease
Neuroblastoma tumors have been clinically staged using surgical and pathological data according to the International Neuroblastoma Staging System (INSS). Stage of disease is correlated with outcome.
Studies of children with stage 1 and 2 neuroblastoma with favorable biologic features report an EFS rate of almost 100%, compared with an event-free survival (EFS) rate of about 50% for those who have unfavorable biological features (i.e., INPC and MYCN gene amplification).[56,57,58] Infants aged 1 year and younger have a greater than 80% cure rate, while older children have a cure rate of 50% to 70% with current, relatively intensive therapy.[59,60,61,62]
Survival of patients with INSS stage 4 disease is strongly dependent on age. Children younger than 1 year at diagnosis have a good chance of long-term survival (i.e., a 5-year disease-free survival rate of 50%–80%),[63,64] with outcome particularly dependent on MYCN amplification and tumor cell ploidy. Hyperdiploidy confers a favorable prognosis while diploidy predicts early treatment failure.[60,65] Infants aged 18 months and younger at diagnosis with INSS stage 4 neuroblastoma who do not have MYCN gene amplification are categorized as intermediate risk.[7,66,67,68]