Acute leukemia and myelodysplasia after adjuvant chemotherapy for breast cancer: durable remissions after hematopoietic stem cell transplantation.

BACKGROUND Although secondary acute leukemias and myelodysplasia are the known complications of adjuvant chemotherapy for breast cancer, the treatment outcome of these secondary malignancies is presently unclear. We examined the clinical and pathological features as well as the treatment results of a series of patients with acute leukemia/myelodysplasia arising after adjuvant chemotherapy for breast cancer. PATIENTS AND METHODS Patients referred to our institution during a 5-year period for treatment of acute leukemia/myelodysplasia and who had received adjuvant chemotherapy for breast cancer are included. Leukemia-free survival for the whole group and for patients who underwent hematopoietic stem cell transplantation (HSCT) was estimated. RESULTS Fifteen women (14 with acute leukemia and one with myelodysplasia) were identified. Seven of 15 patients had received an anthracycline, cyclophosphamide and a taxane. Ten patients developed acute leukemia/myelodysplasia with a latency period of 2 years or less from initiation of chemotherapy. Although mixed-lineage leukemia (MLL) rearrangement was the commonest chromosomal abnormality (8 of 15 patients), various other chromosomal abnormalities were also detected. Twelve of 15 patients underwent HSCT (11 allogeneic and one autologous). Eleven of these 12 patients who underwent HSCT were in remission at a median follow-up of 20.4 months (range 4.4-53.3 months). CONCLUSION Durable remissions can be achieved in patients who develop acute leukemia/myelodysplasia secondary to adjuvant chemotherapy for breast cancer and are able to undergo allogeneic HSCT. Our results indicate that HSCT should be an early consideration in the management of such patients who are suitable candidates for the procedure.