Leukaemia due to mitoxantrone.

(1) Cases of acute leukaemia (usually myeloblastic) have been attributed to mitoxantrone. (2) A French epidemiological study showed an increased risk of leukaemia in women treated with mitoxantrone for breast cancer, with a relative risk of about 7. The results of studies conducted elsewhere are similar. (3) The time to onset of leukaemia after mitoxantrone exposure ranges from 8 months to several years. The risk is dose-dependent. The excess risk is particularly high when the cumulative dose is above 13 mg/m2. The prognosis for leukaemia due to mitoxantrone is worse than the prognosis for leukaemia with no known cause. (4) Cases of leukaemia have also been reported after the use of mitoxantrone to treat other cancers and multiple sclerosis. (5) This serious adverse effect must be taken into account when choosing a treatment for patients with a relatively long life expectancy. Patients treated with mitoxantrone should be monitored.