Abstract
The use of new agents (NAs) such as bortezomib, thalidomide, and lenalidomide has extended the survival of patients with multiple myeloma (MM). However, whether long-term treatment using NAs may increase the risk of second primary malignancies is a concern. Three hundred and thirty-three patients with MM were treated at our hospital from 1998 to 2013. Additional chromosomal abnormalities (CAs), associated with secondary myelodysplastic syndrome/acute myeloid leukemia, were observed in 13 of 152 users of NAs, but in 38 of 181 non-users of NAs. The cumulative CA incidence was higher in non-users of NAs. The CAs frequently observed were 13q-, 20q-, +8 in users of NAs, while -5/5q- and -7/7q- were detected in non-users of NAs. The total dose and treatment period of NAs did not differ between CAs-positive and -negative patients. However, a higher dose of melphalan was observed to have been used in patients who had CAs. Longer follow-up periods are necessary for an accurate risk assessment.