Interferon-alpha in childhood haematological malignancies.

The application of cytostatics has brought about a breakthrough in the treatment of childhood haematological malignancies in the past 20 years. Chemotherapy appears to be least successful in the rare, low and very high mitotic index diseases, which often have an enormous tumour-burden. The suitability of chemotherapy in minimal residual leukaemia is also of some doubt. In these situations a 'conservative' treatment may be more appropriate. Because interferon-alpha has a distinct mechanism of action, and a broad-spectrum haematopoietic inhibitory activity, it is relatively nontoxic and noncancerogenic, and it may have a role in the treatment of malignant haematological disorders, either as a mono- or combination therapy. The exact indications and dosages for interferon in childhood malignancies are far from clear. Up to now, it has proved to be most efficacious in small tumour masses, providing a theoretical basis for application in minimal residual disease. Controlled clinical data, however, are not yet available. It remains to be determined whether or not interferon can be added to current chemotherapy protocols without a significant reduction of dose. Hopefully, a deeper understanding of the activities of interferon will allow us to plan better trials with combination treatments.