Cases of secondary acute myeloid leukemia and myelodysplastic syndrome in patients with multiple myeloma

Summary

Standard chemotherapy using alkylating agents both during the induction of remission and its maintenance therapy had been applied for 30 years in treatment of multiple myeloma (MM). But after a long treatment utilizing alkylating preparations the risk of secondary leukemias becomes unjustified.

We analysed 329 MM cases during the years 1994 to 2008. The males numbered 128 (39%) and the females 201 (61%). The median overall survival (OS) rate for all patients was 31 months. Secondary leukemias were diagnosed in 5 MM patients and were diagnosed as follows: AML (M2 subtype according to FAB) in 2 patients, refractory anemia with excess blasts (RAEB-1 according to WHO) in 2 patients and refractory anemia with excess blasts (RAEB-2 according to WHO) in 1 patient. The median period before a second tumor appeared was 7.3 years. The actuary risk of secondary leukemia after 5 years of MM was 1.3%. The general occurrence of secondary AML and MDS equaled 1.7%. Low occurrence of this phenomenon is due to the fact that the mean period for development of a secondary tumor is 3 times greater than the median life expectancy for MM patients. The median OS rate after the diagnosis of a second leukemia was 2 months.

Thus, secondary AML and MDS are rare complications of chemotherapy in MM patients. But if they appear and develop, it leads to a rapid reduction of life expectancy for the patients because of resistance to the therapy carried out. Patients with smoldering myeloma and a high life expectancy of 5 to 10 years die of a qualitatively new leukemia as a result of a long chemotherapy using alkylating agents. That is why the risk of a second tumor cannot be considered as justified.

Keywords

multiple myeloma, acute myeloid leukemia, myelodysplastic syndrome