Acute myeloid leukemia synchronous with multiple myeloma successfully treated by azacytidine/lenalidomide and daratumumab without a decrease in myeloid clone size

Aberrant DNA methylation in multiple myeloma: A major obstacle or an opportunity?

Drug resistance (DR) of cancer cells leading to relapse is a huge problem nowadays to achieve long-lasting cures for cancer patients. This also holds true for the incurable hematological malignancy multiple myeloma (MM), which is characterized by the accumulation of malignant plasma cells in the bone marrow (BM). Although new treatment approaches combining immunomodulatory drugs, corticosteroids, proteasome inhibitors, alkylating agents, and monoclonal antibodies have significantly improved median life expectancy, MM remains incurable due to the development of DR, with the underlying mechanisms remaining largely ill-defined. It is well-known that MM is a heterogeneous disease, encompassing both genetic and epigenetic aberrations. In normal circumstances, epigenetic modifications, including DNA methylation and posttranslational histone modifications, play an important role in proper chromatin structure and transcriptional regulation. However, in MM, numerous epigenetic defects or so-called ‘epimutations’ have been observed and this especially at the level of DNA methylation. These include genome-wide DNA hypomethylation, locus specific hypermethylation and somatic mutations, copy number variations and/or deregulated expression patterns in DNA methylation modifiers and regulators. The aberrant DNA methylation patterns lead to reduced gene expression of tumor suppressor genes, genomic instability, DR, disease progression, and high-risk disease. In addition, the frequency of somatic mutations in the DNA methylation modifiers seems increased in relapsed patients, again suggesting a role in DR and relapse. In this review, we discuss the recent advances in understanding the involvement of aberrant DNA methylation patterns and/or DNA methylation modifiers in MM development, progression, and relapse. In addition, we discuss their involvement in MM cell plasticity, driving myeloma cells to a cancer stem cell state characterized by a more immature and drug-resistant phenotype. Finally, we briefly touch upon the potential of DNA methyltransferase inhibitors to prevent relapse after treatment with the current standard of care agents and/or new, promising (immuno) therapies.

Synchronous plasma cell neoplasm and B lymphoblastic leukemia/lymphoma at initial presentation: first report of an unusual association with a good outcome

A synchronous diagnosis of a plasma cell neoplasm (PCN) and a non-plasma cell hematologic malignancy is very rare. We report what we believe is the first instance of a synchronous PCN and B lymphoblastic leukemia/lymphoma (B-ALL) diagnosed at initial presentation. The patient underwent laboratory evaluation for an underlying plasma cell neoplasm, including immunology studies, bone marrow biopsy, and flow cytometry immunophenotyping. Serum lambda free light chain and serum IgG were elevated, with an IgG lambda M-protein identified by serum protein electrophoresis and immunofixation. The clinical working diagnosis was plasma cell myeloma. Bone marrow biopsy was positive for a composite PCN and B-ALL. The patient received treatment with VDT-PACE chemotherapy followed by autologous stem cell transplant and maintenance therapy with bortezomib/daratumumab and is in complete remission for both diseases 3.5 years after diagnosis. This case not only adds to the known repertoire of hematologic neoplasms that can occur in association to a PCN, but also demonstrates that patients presenting with this rare combination of hematopoietic neoplasms can be effectively treated simultaneously with excellent responses. Additional research is warranted to understand the pathophysiology, to identify potential prognostic factors, and to develop specific therapeutic plans for these patients.