Conventional and molecular cytogenetic analyses in Turkish patients with multiple myeloma

Pros and Cons for Fluorescent in Situ Hybridization, Karyotyping and Next Generation Sequencing for Diagnosis and Follow-up of Multiple Myeloma

Multiple myeloma (MM) is one of the plasma cell-related hematological malignancies exceeding 10.0% of all marrow cells, and they make a paraprotein that is a marker of the disease. Myeloma is one of the most common types of hematological malignancies in humans. Genetic bio-markers have been used for prognostic markers in patients diagnosed with MM. The genetic and genomic changes have been identified using karyotyping, fluorescent in situ hybridization (FISH), next generation sequencing (NGS), specifically whole-genome sequencing or exome sequencing. Circulatory plasma cells, circulating free DNA (cfD-NA) and microRNAs (miRNAs) comprised in liquid biopsy are potentially used in diagnosis/prognosis of MM. In this study, we analyzed and compared results of karyo-typing, FISH and NGS in 35 MM cases. Diagnostic strategies are expanding rapidly and newly developed NGS-based testing may help the understanding of the complexities of genetic alterations in karyotypically normal cases.

Conventional Cytogenetics and Interphase Fluorescence In Situ Hybridization Results in Multiple Myeloma: A Turkey Laboratory Analysis of 381 Cases

Multiple myeloma (MM) is an uncontrolled proliferation of plasma cells and these cells play an important role in the immune system. In this research, we retrospectively analyzed cytogenetic abnormalities in 381 patients with MM. Conventional cytogenetic analysis was successful in 354 patients (92.9%). Chromosomal abnormalities were detected in 31.9% (113/354) and 45.8% (116/253) of patients screened with conventional cytogenetics and FISH, respectively. Of 113 patients with chromosomal abnormalities, 31 patients (27.4%) had hyperdiploid and 26 of 31 patients with hyperdiploidy had both numerical and structural anomalies. On the other hand, non-hyperdiploidy was observed in 62 patients (54.8%). The most common gains of chromosomes were 15, 9, 19 followed by 3, 5, 11, and 21. Whole chromosome losses were also frequent involving Y, 13 and 22 chromosomes. In our patients, 1q gain was determined in a total of 25 patients (22%), including 7 structural abnormalities and 19 unbalanced translocations causing complete or partial duplication of the long arm of chromosome 1. Although the breakpoints were different, t(1;5) balanced translocation and unbalanced translocations of t(1;2), t(1;3), t(1;7), t(1;16) and t(1;19) were observed twice. The most common structural abnormality was the deletion of the short arm of chromosome 13 (13q) or monosomy of chromosome 13 (-13) (24.1%, 61/253) in patients evaluated by FISH. Deletion involving chromosome 17p (del 17p) or monosomy of chromosome 17 (-17) were found in 31 (12.3%) patients. Translocations involving IgH regions were as follows: t(11;14)(q13;q32.33) in 22 (8.7%), t(4;14)(p16.3;q32.33) in 22 (8.7%) and t(14;16)(q32.33;q23.1) in 2 (0.8%) patients. In addition, t(14;17)(q32;q21) translocation was detected in a multiple myeloma patient for the first time in this study. There are a limited number of large study groups including both cytogenetic and FISH findings in MM patients. As the number of these studies increases, it is thought that new cytogenetic data can be guiding especially in clinical risk determination.

Development of an Initial Conceptual Model of Multiple Myeloma to Support Clinical and Health Economics Decision Making

Background. We aimed to develop and validate a conceptual model of multiple myeloma (MM) that characterizes the attributes affecting disease progression and patient outcomes, and the relationships between them. Methods. Systematic and targeted literature reviews identified disease- and patient-specific attributes of MM that affect disease progression and outcomes. These attributes were validated by a Delphi panel of four international MM experts, and a physician-validated model was constructed. Real-world clinical data from the Czech Registry of Monoclonal Gammopathies (RMG) was used to confirm the relationships between attributes using pairwise correlations and multiple Cox regression analysis. Results. The Delphi panel reached consensus that most cytogenetic abnormalities influenced disease activity, which results in symptoms and complications and affects overall survival (OS). Comorbidities and complications also affect OS. The entire panel agreed that quality of life was influenced by comorbidities, age, complications, and symptoms. Consensus was not reached in some cases, in particular, the influence of del(17p) on complications. The relationships between attributes were confirmed using pairwise analysis of real-world data from the Czech RMG; most of the correlations identified were statistically significant and the strength of the correlations changed with successive relapses. Czech RMG data were also used to confirm significant predictors of OS included in the model, such as age, Eastern Cooperative Oncology Group performance status, and extramedullary disease. Conclusions. This validated conceptual model can be used for economic modeling and clinical decision making. It could also inform the development of disease-based models to explore the impact of disease progression and treatment on outcomes in patients with MM.