chemical / drug causes
Last reviewed 01/2018
Many drugs are capable of damaging bone marrow elements, giving rise to acute leukaemia, marrow aplasia or myelodysplasia. The most important are the aromatic hydrocarbon solvents and glues such as benzene, toluene, xylene and naphthalene. Others include pesticides, dyes and industrial toxins.
Cytotoxic and immunosuppressive agents used to treat malignant and non-malignant conditions are also associated with an increased risk of leukaemic transformation. The risk is proportional to the dose and duration of exposure and is greatest with alkylating agents, e.g. melphalan. Patients receiving both radiotherapy and chemotherapy are particularly susceptible.
Leukaemias that are seen after toxin exposure often develop from a myelodysplastic syndrome and are associated with abnormalities in chromosomes 5 and 7.