Neuroblastoma Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Treatment Option Overview for Neuroblastoma
Table 5. Treatment Options for Neuroblastoma continued...
Children's Oncology Group (COG) Neuroblastoma Risk Grouping
The treatment section of this document is organized to correspond with the COG risk-based treatment plan that assigns all patients to a low-, intermediate-, or high-risk group. This risk-based schema is based on the following factors:
- Patient age at diagnosis.
- Certain biological characteristics of the tumor, which include MYCN status, INPC histopathology classification, and tumor DNA index.
- Stage of the tumor as defined by the INSS.
Table 6 (in the Treatment of Low-Risk Neuroblastoma section), Table 7 (in the Treatment of Intermediate-Risk Neuroblastoma section), and Table 8 (in the Treatment of High-Risk Neuroblastoma section) describe the risk group assignment criteria used to assign treatment in the COG-P9641, COG-A3961, and COG-A3973 studies, respectively.
Assessment of risk for low-stage MYCN-amplified neuroblastoma is controversial because it is so rare. A study of 87 INSS stage 1 and 2 patients pooled from several clinical trial groups demonstrated no effect of age, stage, or initial treatment on outcome. The event-free survival (EFS) rate was 53% and the OS rate was 72%. Survival was superior in patients whose tumors were hyperdiploid, rather than diploid (EFS, 82% ± 20% vs. 37% ± 21%; OS, 94% ± 11% vs. 54% ± 15%). The overall EFS and OS for infants with stage 4 and 4S disease and MYCN-amplification was only 30% at 2 to 5 years after treatment in a European study. The COG considers infants with stage 4 and stage 4S disease with MYCN amplification to be at high risk.
Description of International Neuroblastoma Response Criteria
Before therapy can be stopped after the initially planned number of cycles, certain response criteria, depending on risk group and treatment assignment, must be met. These criteria are defined as follows:[13,14]
Complete Response: Total disappearance of tumor, with no evidence of disease. Vanillylmandelic acid (VMA) and homovanillic acid (HVA) are normal.
Very Good Partial Response: Primary tumor has decreased by 90% to 99%, and no evidence of metastatic disease. Urine VMA/HVA are normal. Residual bone scan changes are allowed.
Partial Response: 50% to 90% decrease in the size of all measurable lesions; the number of bone scan-positive sites is decreased by greater than 50% and no new lesions are present; no more than one positive bone marrow site allowed if this represents a reduction in the number of sites originally positive for tumor at diagnosis.
Mixed Response: No new lesions, 50% to 90% reduction of any measurable lesion (primary or metastatic) with less than 50% reduction in other lesions and less than 25% increase in any lesion.
No Response or Stable Disease: No new lesions; less than 50% reduction and less than 25% increase in any lesion.
Progressive Disease: Any new lesion; increase in any measurable lesion by greater than 25%; previous negative bone marrow now positive for tumor. Persistent elevation in urinary VMA/HVA with stable disease or an increase in VMA/HVA without clinical or radiographic evidence of progression does not indicate progressive disease, but warrants continued follow-up. Care should be taken in interpreting the development of metastatic disease in an infant who was initially considered to have stage 1 or 2 disease. If the pattern of metastases in such a patient is consistent with a 4S pattern of disease (skin, liver, bone marrow less than 10% involved), these patients are not classified as progressive/metastatic disease, which would typically be a criteria for removal from protocol therapy. Instead, these patients are managed as stage 4S.