[Four cases of therapy-related leukemia in multiple myeloma]

We have experienced 4 cases of therapy-related leukemia (TRL) in 119 patients with multiple myeloma (MM) who had received combination chemotherapy including alkylating agents between 1988 and 1998. All 4 cases were acute myelogenous leukemia, 3 were males and 1 was female. Median age at diagnosis of MM was 60 years, and median time to TRL from diagnosis of MM was 5.5 years. The chromosome abnormalities were found in 3 of those cases. All 4 cases were resistant to antileukemic chemotherapy, and median survival time from TRL was only 5.5 months. The TRL in MM is thought to be a more important problem, because recently the treatment for this disease has become more intensive, including high-dose chemotherapy supported by autologous stem cell transplantation.