Waldenström's macroglobulinaemia: Current therapy and future approaches

Waldenström's macroglobulinaemia is a rare B-cell malignancy. It is prevalent in the sixth and seventh decades, the median age at diagnosis being 63 years. Conventional treatment has involved alkylator therapy, especially chlorambucil given daily at a low dose or intermittently at a higher dose. Purine analogues, used initially as salvage therapy in refractory disease, are increasingly used for initial therapy. However, purine analogue therapy entails significant complications, including immunosuppression, pancytopenia and autoimmune haemolysis. Moreover, it is unclear whether purine analogues extend survival. All of these need to be considered before initiation of therapy. More recently, anti-CD20 monoclonal antibody and thalidomide have been used with a 30% response in treated patients. High-dose therapy with stem cell support achieves a partial response in a majority of patients receiving this modality of therapy. The median survival of 5 years has not improved considerably since the introduction of purine analogues. Complete response is still uncommon; using all available modalities of therapy may increase the complete response rate and improve survival. Great strides in understanding the malignant cell, the microenvironment and the potential interactions have identified potential targets for therapy in multiple myeloma. These agents may also be useful in Waldenström's macroglobulinaemia. Since this is a rare malignancy, all patients should be treated with well-designed clinical protocols to achieve improvement in outcome.