[Leukemia and pre-leukemic conditions occurring after treatment of breast cancer]

The purpose of this study was to determine the clinical and prognostic features of leukemias and preleukemic states, whatever the mode of development, observed in patients after treatment of breast cancer.

A retrospective multicentric analysis was made of 121 patients treated for breast cancer and who later developed leukemia or a preleukemic state. Initially, 44 patients had undergone mastectomy, 72 had conservative surgery and 119 had locoregional irradiation. At least one chemotherapy session was performed in 90 patients and 48 had received tamoxifen. The risk of relapse of breast cancer was high, moderate or low for 44, 46 and 24 patients respectively (data not available for 7 patients).

By class, the hematology diseases found were: myelodysplasia (n = 9), refractory anemia with blast excess (n = 7), acute lymphoblastic leukemia (n = 6), acute myoblastic leukemia (n = 93 including a majority of type 2 and type 4). For acute myeloblastic leukemia, mean delay to onset was 65 and 37 months respectively without and after chemotherapy. The prognosis of these cases of leukemia and preleukemic states was poor with an overall death rate of 86%.

In light of the recent development of indications for adjuvant chemotherapy even for subgroups of patients at moderate risk, it is important to more precisely assess the absolute benefit in terms of survival compared with the risk of severe complications, particular secondary leukemia. In the future, a systematic registry and a case-control study are required.