Clonal myelodysplastic cells present in apheresis product before transplantation

Second malignancies after multiple myeloma: from 1960s to 2010s

Based on small numbers, recent reports from 3 randomized trials have consistently demonstrated more hematologic malignancies in patients treated with lenalidomide as maintenance (vs placebo). This fact has prompted concern and highlighted the association between multiple myeloma and second malignancies. Furthermore, an excess of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) after multiple myeloma has been known for over 4 decades. Most prior studies have been restricted because of small numbers of patients, inadequate follow-up, and limitations of ascertainment of second malignancies. Although the underlying biologic mechanisms of AML/MDS after multiple myeloma are unknown, treatment-related factors are presumed to be responsible. Recently, an excess risk of AML/MDS was found among 5652 patients with IgG/IgA (but not IgM) monoclonal gammopathy of undetermined significance, supporting a role for disease-related factors. Furthermore, there is evidence to suggest that polymorphisms in germline genes may contribute to a person's susceptibility to subsequent cancers, whereas the potential influence of environmental and behavioral factors remains poorly understood. This review discusses current knowledge regarding second malignancies after multiple myeloma and gives future directions for efforts designed to characterize underlying biologic mechanisms, with the goal to maximize survival and minimize the risk for second malignancies for individual patients.

Myelodysplastic syndrome after autologous peripheral blood stem cell transplantation for multiple myeloma

Long-term survivors after autologous peripheral blood stem cell transplantation (APBSCT) for lymphoma or Hodgkin's disease are known to have a high risk of developing myelodysplastic syndrome (MDS), but the risk of MDS is not clear for patients transplanted for myeloma. We reviewed the outcomes for 82 myeloma patients who underwent APBSCT at our center. The group included 47 men and 35 women of median age 56 years (range: 37-74 years). Median time from diagnosis to APBSCT was 8.2 months (range: 2.6-86.1 months). Before coming to transplantation, 28% had received oral melphalan (MEL), 98% received other chemotherapy and 34% received radiation. A single APBSCT was provided for 68, and 32% underwent APBSCT more than once. High-dose MEL alone was used as the preparative regimen for 83%, and the remainder received at least one APBSCT with a more intensive preparative regimen. Ten patients (12%) developed MDS. The 5-year cumulative incidence is 18% (95% confidence interval, 9-30%). There were no demographic factors associated with an increased risk of developing MDS. Median survival after the diagnosis of MDS was 18 months. There is a relatively high risk of MDS after APBSCT for myeloma, and optimal therapy has not been established for these patients.

Secondary myelodysplastic syndrome and acute myelogenous leukemia are significant complications following autologous stem cell transplantation for lymphoma

Secondary myelodysplastic syndrome (sMDS) and acute myelogenous leukemia (AML) have been recognized with increasing frequency following autologous stem cell transplantation (ASCT). A retrospective analysis of 230 consecutive patients with Hodgkin's lymphoma (HL, 64) and non-Hodgkin's lymphoma (NHL, 166) who underwent ASCT was conducted to assess the incidence and risk factors for the development of sMDS/AML. At a median follow up of 41 months (range 0.1-177 months), 10 of 230 patients (4.3%) developed sMDS/AML. The 5-year-actuarial incidence of sMDS/AML was 13.1% and 5-year cumulative incidence by competing risk analysis was 4.2%. The median time to development of sMDS/AML was 39.9 months from the time of ASCT (range 12.1-62.0 months). Complex karyotypes at diagnosis of sMDS/AML included structural anomalies and/or loss of chromosome 5 (eight patients), 7 (five patients), 17 (two patients) and 20 (two patients). All patients subsequently died, at a median of 6.8 months (range 0-39.9) from diagnosis of sMDS/AML. Fluorescent in situ hybridization (FISH) analysis for -5/5q- and -7/7q- were normal in all six patients whose pre-ASCT bone marrow was available for testing. Five of the six had samples available for testing at diagnosis of sMDS/AML and all had abnormal FISH results. By univariate statistical analysis, male gender (P=0.01), prior alkylating agents (mechlorethamine for HL, P=0.001 and cyclophosphamide for NHL, P=0.05) and the number of prior treatment regimens (P=0.04) were significantly associated with the development of sMDS/AML. Given the relatively low incidence rate of sMDS/AML, these analyses are primarily exploratory in nature but provide some insight into relevant risk factors and illustrate the risk of developing sMDS/AML after myeloablative conditioning and ASCT for lymphoma.

Chromosomal abnormalities in women with breast cancer after autologous stem cell transplantation are infrequent and may not predict development of therapy-related leukemia or myelodysplastic syndrome

We determined prospectively the incidence of chromosomal abnormalities in patients with high-risk breast cancer (HRBC) after high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT), and correlated the cytogenetic abnormalities with the development of post-transplant myelodysplastic syndrome or acute myeloid leukemia (MDS/AML). From 1990 to 1999, 229 women with HRBC underwent ASCT. Cytogenetic analysis of bone marrow (BM) cells was performed 12-59 months after ASCT in 60 consecutive women uniformly treated with six courses of FAC/FEC followed by HDCT and ASCT. With a median follow-up of 36 months after ASCT, there were no cases of MDS/AML among the 229 patients. In the selected cohort of 60 patients, three (5%) showed clonal chromosomal abnormalities (two single trisomy X and one t(1;6)), whereas two additional patients showed non-clonal reciprocal translocations. Two of the patients with clonal aberrations had blood cytopenias as well as subtle dysplastic pictures in BM which were not classifiable as MDS according to the FAB criteria. Similar dysplastic features were also observed in four patients with normal karyotypes. All cytogenetic aberrations were transient and disappeared, except a +X detected by FISH in a residual cell population in one of the patients. Retrospective cytogenetic and FISH studies of samples obtained after six cycles of FAC/FEC and before transplant demonstrated no chromosomal abnormalities in any of the five patients with post-ASCT karyotypic changes. Early changes in karyotype detected in breast cancer patients following ASCT are transient and do not correlate with or predict development of MDS/AML. As these aberrations were not present before ASCT, they may be related to the HDCT regimen or transplant procedure rather than to the prior adjuvant therapy. Our results suggest that ASCT may be less likely to cause MDS or AML in breast cancer patients as compared to other malignancies. Bone Marrow Transplantation (2000) 25, 1203-1208.