High dose chlorambucil in the treatment of lymphoid malignancies.

High dose chlorambucil has been shown to be an effective single-agent treatment in chronic lymphocytic leukemia (CLL), and to be useful as part of combination chemotherapy in low-grade non-Hodgkin's (NHL) and Hodgkin's disease (HD). In general, it is well tolerated and can be used in an outpatient setting. The optimum dose of chlorambucil has not been defined and there are numerous different dosing schedules available. Pharmacokinetic studies suggest decreased bioavailability with successive cycles, probably due to accelerated metabolism. There is good evidence that regimens which use higher doses of chlorambucil have a better outcome than standard dose therapy. Most of the trials which have compared chlorambucil with fludarabine have not used a higher dose regimen of chlorambucil and cannot truly be described as comparative. There is an increase in the incidence of grade 3 and 4 neutropenia and also of sepsis with fludarabine treatment, compared to chlorambucil. Fludarabine produces a higher initial response rate in CLL but no statistical difference has been shown in long term survival between fludarabine and high dose chlorambucil. In the treatment of lymphoma, single agent chlorambucil does not confer a durable remission. There have been good results with combination chemotherapy regimens such as CID and PECC. The oral route of administration of these combinations makes them particularly useful as part of palliative chemotherapy. A further point to consider is that chlorambucil is very much cheaper than fludarabine and other newer agents. Chlorambucil should not automatically be overlooked in favor of more recently developed drugs such as fludarabine. There is good evidence that the drug is an effective treatment at a suitable dose, and there is a need for randomized trials to compare it fully with other current treatments.