Neuroblastoma: current drug therapy recommendations as part of the total treatment approach.

Neuroblastoma represents one of the most challenging malignancies for treatment decisions because of its unusual biological behaviour. The features include spontaneous regression (regressive type), maturation to ganglioneuroma (maturative type) and largely treatment-resistant progression (progressive type). Current knowledge allows only partial prediction of type. For practical reasons, patients may be categorised as an 'observation', a 'standard risk' or a 'high risk' treatment arm. During the last 2 decades, 5-year survival rates for children with neuroblastoma have increased from 48 to 67%. The main achievements were the reduction of chemotherapy in patients with localised disease and the increased efficacy of chemotherapy in metastatic neuroblastoma stage 4 (5-year survival increased from 8 to 33%). Different goals for chemotherapy (e.g. stopping rapid progression, improvement of symptoms, induction and maintenance of remission) require different dosages and durations of treatment (range 1 week to 9 months). The main risks of chemotherapy are toxic death (rate up to 15%) predominantly during the periods of bone marrow depression and the development of secondary leukaemias (up to 7% cumulative risk after 4 years). In conclusion, the use of cytotoxic drugs can be completely omitted in a substantial proportion of low risk patients with neuroblastoma. On the other hand, for high risk patients with the disease, intensive polychemotherapy represents the basis and the backbone of treatment among other modalities.