Increase therapy-related leukemia secondary to breast cancer

Therapy-related leukemia associated with chemotherapy, particularly alkylat ing agents and topoisomerase II inhibitors, are being reported with increas ing frequency in the literature mainly after breast cancer. We also observe d an increasing number of such leukemias in the data base of the specialize d registry of hematological malignancies of the Cote d'Or department. Betwe en 1980 end 1998, 156 AML and RAEB-t were registered in women in Cote d'Or. Among them, 12 occurred in women with breast cancer history (7.7%). Analys is by period of time shows a significant increase in the proportion of ther apy-related leukemia secondary to breast cancer (P < 0.02). Chemotherapy in cluding topoisomerase II inhibitors was used in 10 cases in which mitoxantr one was used in eight cases. In these eight cases, leukemia had clinical an d biological characteristics usually described with topoisomerase II inhibi tors but 44% were promyelocytic sub-type with the t(15;17) specific karyoty pic abnormality. These data on a well-defined population demonstrate the in creased proportion of therapy-related leukemia secondary to breast cancer, probably due to the use of mitoxantrone.