Deletion of chromosome 13 detected by conventional cytogenetics is a critical prognostic factor in myeloma

Trisomies in multiple myeloma: impact on survival in patients with high-risk cytogenetics

Routine incorporation of FISH into multiple myeloma (MM) diagnostic testing has led to a better appreciation of the heterogeneity of genetic abnormalities associated with this disease. We studied a group of 484 patients with newly diagnosed symptomatic MM to better understand the prevalence of the various abnormalities and the prognostic significance of the overlapping abnormalities. A translocation involving the IgH locus and 1 of the 5 recurrent partner chromosomes was seen in 161 (33%) patients, and 275 (57%) had trisomy of at least 1 odd-numbered chromosome. High-risk FISH, defined as the presence of t(4;14), t(14;16), t(14;20), or loss of P53, was seen in 115 (24%) patients; the median overall survival for this group was 3.9 years, compared with "not reached" for standard-risk patients (P < .001). Among the patients with high-risk FISH, 49 patients who also had at least 1 trisomy had a median overall survival that was not reached, compared with 3 years for high-risk patients without a concurrent trisomy (P = .01). Based on the current findings, we conclude that the presence of trisomies in patients with t(4;14), t(14;16), t(14;20), or p53 deletion abnormalities in MM ameliorates the usual adverse impact associated with these prognostic markers.

The clinical impact and molecular biology of del(17p) in multiple myeloma treated with conventional or thalidomide-based therapy

Hemizygous deletion of 17p (del(17p)) has been identified as a variable associated with poor prognosis in myeloma, although its impact in the context of thalidomide therapy is not well described. The clinical outcome of 85 myeloma patients with del(17p) treated in a clinical trial incorporating both conventional and thalidomide-based induction therapies was examined. The clinical impact of deletion, low expression, and mutation of TP53 was also determined. Patients with del(17p) did not have inferior response rates compared to patients without del(17p), but, despite this, del(17p) was associated with impaired overall survival (OS) (median OS 26.6 vs. 48.5 months, P < 0.001). Within the del(17p) group, thalidomide induction therapy was associated with improved response rates compared to conventional therapy, but there was no impact on OS. Thalidomide maintenance was associated with impaired OS, although our analysis suggests that this effect may have been due to confounding variables. A minimally deleted region on 17p13.1 involving 17 genes was identified, of which only TP53 and SAT2 were underexpressed. TP53 was mutated in <1% in patients without del(17p) and in 27% of patients with del(17p). The higher TP53 mutation rate in samples with del(17p) suggests a role for TP53 in these clinical outcomes. In conclusion, del(17p) defined a patient group associated with short survival in myeloma, and although thalidomide induction therapy was associated with improved response rates, it did not impact OS, suggesting that alternative therapeutic strategies are required for this group.

Administration of bortezomib before and after autologous stem cell transplantation improves outcome in multiple myeloma patients with deletion 17p

In patients with multiple myeloma (MM), risk stratification by chromosomal abnormalities may enable a more rational selection of therapeutic approaches. In the present study, we analyzed the prognostic value of 12 chromosomal abnormalities in a series of 354 MM patients treated within the HOVON-65/GMMG-HD4 trial. Because of the 2-arm design of the study, we were able to analyze the effect of a bortezomib-based treatment before and after autologous stem cell transplantation (arm B) compared with standard treatment without bortezomib (arm A). For allanalyzed chromosomal aberrations, progression-free survival (PFS) and overall survival (OS) were at least equal or superior in the bortezomib arm compared with the standard arm. Strikingly, patients with del(17p13) benefited the most from the bortezomib-containing treatment: the median PFS in arm A was 12.0 months and in arm B it was 26.2 months (P = .024); the 3 year-OS for arm A was 17% and for arm B it was 69% (P = .028). After multivariate analysis, del(17p13) was an independent predictor for PFS (P < .0001) and OS (P < .0001) in arm A, whereas no statistically significant effect on PFS (P = .28) or OS (P = .12) was seen in arm B. In conclusion, the adverse impact of del(17p13) on PFS and OS could be significantly reduced by bortezomib-based treatment, suggesting that long-term administration of bortezomib should be recommended for patients carrying del(17p13).

Common variation at 3p22.1 and 7p15.3 influences multiple myeloma risk

To identify risk variants for multiple myeloma, we conducted a genome-wide association study of 1,675 individuals with multiple myeloma and 5,903 control subjects. We identified risk loci for multiple myeloma at 3p22.1 (rs1052501 in ULK4; odds ratio (OR) = 1.32; P = 7.47 × 10(-9)) and 7p15.3 (rs4487645, OR = 1.38; P = 3.33 × 10(-15)). In addition, we observed a promising association at 2p23.3 (rs6746082, OR = 1.29; P = 1.22 × 10(-7)). Our study identifies new genomic regions associated with multiple myeloma risk that may lead to new etiological insights.

Mapping of chromosome 1p deletions in myeloma identifies FAM46C at 1p12 and CDKN2C at 1p32.3 as being genes in regions associated with adverse survival

PURPOSE

Regions on 1p with recurrent deletions in presenting myeloma patients were examined with the purpose of defining the deletions and assessing their survival impact.

EXPERIMENTAL DESIGN

Gene mapping, gene expression, FISH, and mutation analyses were conducted on patient samples from the MRC Myeloma IX trial and correlated with clinical outcome data.

RESULTS

1p32.3 was deleted in 11% of cases, and deletion was strongly associated with impaired overall survival (OS) in patients treated with autologous stem cell transplant (ASCT). In patients treated less intensively, del(1)(p32.3) was not associated with adverse progression-free survival (PFS) or OS. The target of homozygous deletions was CDKN2C, however its role in the adverse outcome of cases with hemizygous deletion was less certain. 1p22.1-21.2 was the most frequently deleted region and contained the candidate genes MTF2 and TMED5. No mutations were identified in these genes. 1p12 was deleted in 19% of cases, and deletion was associated with impaired OS in univariate analysis. The target of homozygous deletion was FAM46C, which was mutated in 3.4% of cases. When cases with FAM46C deletion or mutation were considered together, they were strongly associated with impaired OS in the intensive treatment setting.

CONCLUSION

Deletion of 1p32.3 and 1p12 was associated with impaired OS in myeloma patients receiving ASCT. FAM46C was identified as a gene with potential pathogenic and prognostic significance based on the occurrence of recurrent homozygous deletions and mutations.

Gene expression profiling in multiple myeloma--reporting of entities, risk, and targets in clinical routine

PURPOSE

Multiple myeloma is an incurable malignant plasma cell disease characterized by survival ranging from several months to more than 15 years. Assessment of risk and underlying molecular heterogeneity can be excellently done by gene expression profiling (GEP), but its way into clinical routine is hampered by the lack of an appropriate reporting tool and the integration with other prognostic factors into a single "meta" risk stratification.

EXPERIMENTAL DESIGN

The GEP-report (GEP-R) was built as an open-source software developed in R for gene expression reporting in clinical practice using Affymetrix microarrays. GEP-R processes new samples by applying a documentation-by-value strategy to the raw data to be able to assign thresholds and grouping algorithms defined on a reference cohort of 262 patients with multiple myeloma. Furthermore, we integrated expression-based and conventional prognostic factors within one risk stratification (HM-metascore).

RESULTS

The GEP-R comprises (i) quality control, (ii) sample identity control, (iii) biologic classification, (iv) risk stratification, and (v) assessment of target genes. The resulting HM-metascore is defined as the sum over the weighted factors gene expression-based risk-assessment (UAMS-, IFM-score), proliferation, International Staging System (ISS) stage, t(4;14), and expression of prognostic target genes (AURKA, IGF1R) for which clinical grade inhibitors exist. The HM-score delineates three significantly different groups of 13.1%, 72.1%, and 14.7% of patients with a 6-year survival rate of 89.3%, 60.6%, and 18.6%, respectively.

CONCLUSION

GEP reporting allows prospective assessment of risk and target gene expression and integration of current prognostic factors in clinical routine, being customizable about novel parameters or other cancer entities.

Myelomatous pleural effusion: a case series in a single institution and literature review

Background

Myelomatous pleural effusion (MPE) is rare in myeloma patients. We present a consecutive series of patients with MPE in a single institution.

Methods

We retrospectively reviewed the medical records of 19 patients diagnosed with MPE between 1989 and 2008 at the Asan Medical Center. Diagnoses were confirmed by cytologic identification of malignant plasma cells in the pleural fluid.

Results

Our patients showed dominance of IgA (36.8%) and IgD (31.6%) subtypes. Of 734 myeloma patients, the incidence of MPE was remarkably high for the IgD myeloma subtype (16.7%), compared to the other subtypes (1.4% for IgG and 4.6% for IgA). At the time of diagnosis of MPE, elevated serum β2-microglobulin, anemia, elevated serum lactate dehydrogenase, and elevated creatinine levels were found in 100%, 89.5%, 83.3%, and 57.9% of the patients, respectively. Approximately one-third (31.3%) of the patients had adenosine deaminase (ADA) activities in their pleural fluid exceeding the upper limit of the reported cutoff values for tuberculous pleural effusion (55.8 U/L). Chromosome 13 abnormality was seen in 77.8% of the tested patients. The median survival period from the development of MPE was 2.8 months.

Conclusions

Patients with MPE have aggressive clinical and laboratory characteristics. The preponderance of IgD myeloma in MPE patients is a noteworthy finding because IgD myeloma is a rare subtype. Elevated ADA activity in the pleural fluid is also noteworthy, and may be helpful for detecting MPE. Physicians treating myeloma patients should monitor the development of MPE and consider the possibility of a worse clinical course.

Genetic markers used for risk stratification in multiple myeloma

While no specific genetic markers are required in the diagnosis of multiple myeloma (MM), multiple genetic abnormalities and gene signatures are used in disease prognostication and risk stratification. This is particularly important for the adequate identification of the high-risk MM group, which does not benefit from any of the current therapies, and novel approaches need to be proposed. Fluorescence in situ hybridization (FISH) has been employed for establishing risk-based stratification and still remains the most used genetic technique in the clinical routine. The incorporation of gene expression profiling (GEP) in the study of MM has shown to be a very powerful test in the patient stratification, but its incorporation in clinical routine depends on some technical and logistic resolutions. Thus, FISH still remains the gold standard test for detecting genomic abnormalities and outcome discrimination in MM.

A novel prognostic model in myeloma based on co-segregating adverse FISH lesions and the ISS: analysis of patients treated in the MRC Myeloma IX trial

The association of genetic lesions detected by FISH with survival was analyzed in 1069 patients with newly presenting myeloma treated in the Medical Research Council (MRC) Myeloma IX trial, with the aim of identifying patients associated with the worst prognosis. A comprehensive FISH panel was performed, and the lesions associated with short PFS and OS in multivariate analysis were +1q21, del(17p13) and an adverse IGH translocation group incorporating t(4;14), t(14;16) and t(14;20). These lesions frequently co-segregated, and there was an association between the accumulation of these adverse FISH lesions and a progressive impairment of survival. This observation was used to define a series of risk groups based on number of adverse lesions. Taking this approach we defined a favorable risk group by the absence of adverse genetic lesions, an intermediate group with 1 adverse lesion and a high risk group defined by the co-segregation of >1 adverse lesion. This genetic grouping was independent of the ISS and so was integrated with the ISS to identify an ultra-high risk group defined by ISS II or III and >1 adverse lesion. This group constituted 13.8 % of patients and was associated with a median OS of 19.4 months.

Impact of genetic abnormalities after allogeneic stem cell transplantation in multiple myeloma: a report of the Société Française de Greffe de Moelle et de Thérapie Cellulaire

BACKGROUND

The impact of cytogenetic abnormalities in multiple myeloma after allogeneic stem cell transplantation has not been clearly defined. This study examines whether allogeneic stem cell transplantation could be of benefit for myeloma patients with high-risk cytogenetic abnormalities.

DESIGN AND METHODS

This is a retrospective multicenter analysis of the registry of the Société Française de Greffe de Moelle et de Thérapie Cellulaire, including 143 myeloma patients transplanted between 1999 and 2008.

RESULTS

The incidences of cytogenetic abnormalities were 59% for del(13q), 25% for t(4;14), 25% for del(17p) and 4% for t(14;16). When comparing the population carrying an abnormality to that without the same abnormality, no significant difference was found in progression-free survival, overall survival or progression rate. Patients were grouped according to the presence of any of the poor prognosis cytogenetic abnormalities t(4;14), del(17p) or t(14;16) (n=53) or their absence (n=32). No difference in outcomes was observed between these two groups: the 3-year progression-free survival, overall survival and progression rates were 30% versus 17% (P=0.9), 45% versus 39% (P=0.8) and 53% versus 75% (P=0.9), respectively.

CONCLUSIONS

These data indicate that allogeneic stem cell transplantation could potentially be of benefit to high-risk myeloma patients.

Gender disparities in the tumor genetics and clinical outcome of multiple myeloma

BACKGROUND

Several cancer types have differences in incidence and clinical outcome dependent on gender, but these are not well described in myeloma. The aim of this study was to characterize gender disparities in myeloma.

METHODS

We investigated the association of gender with the prevalence of tumor genetic lesions and the clinical outcome of 1,960 patients enrolled in the phase III clinical trial MRC Myeloma IX. Genetic lesions were characterized by FISH.

RESULTS

Disparities were found in the prevalence of primary genetic lesions with immunoglobulin heavy chain gene (IGH) translocations being more common in women (50% of female patients vs. 38% of male patients, P < 0.001) and hyperdiploidy being more common in men (50% female vs. 62% male, P < 0.001). There were also differences in secondary genetic events with del(13q) (52% female vs. 41% male, P < 0.001) and +1q (43% female vs. 36% male, P = 0.042) being found more frequently in female myeloma patients. Female gender was associated with inferior overall survival (median: 44.8 months female vs. 49.9 months male, P = 0.020).

CONCLUSIONS

We found gender-dependent differences in the prevalence of the primary genetic events of myeloma, with IGH translocations being more common in women and hyperdiploidy more common in men. This genetic background may impact subsequent genetic events such as +1q and del(13q), which were both more frequent in women. The higher prevalence of lesions associated with poor prognosis in the female myeloma population, such as t(4;14), t(14;16) and +1q, may adversely affect clinical outcome.

IMPACT

These differences suggest that gender influences the primary genetic events of myeloma.

Hyperdiploidy is less frequent in AL amyloidosis compared with monoclonal gammopathy of undetermined significance and inversely associated with translocation t(11;14)

In multiple myeloma (MM) pathogenesis, hyperdiploidy and nonhyperdiploidy are recognized as 2 major cytogenetic pathways. Here, we assessed the role of hyperdiploidy in 426 patients with monoclonal plasma cell disorders, among them 246 patients with AL amyloidosis (AL), by interphase fluorescence in situ hybridization. Hyperdiploidy was defined by a well-established score requiring trisomies for at least 2 of the 3 chromosomes 5, 9, and 15. The hyperdiploidy frequency in AL was a mere 11% compared with 30% in monoclonal gammopathy of undetermined significance (P < .001) and 46% in AL with concomitant MM I (P < .001). Overall, hyperdiploidy was associated with an intact immunoglobulin, κ light chain restriction, higher age, and bone marrow plasmacytosis, but was unrelated to the organ involvement pattern in AL. Clustering of 6 major cytogenetic aberrations in AL by an oncogenetic tree model showed that hyperdiploidy and t(11;14) were almost mutually exclusive, whereas gain of 1q21 favored hyperdiploidy. Deletion 13q14 and secondary IgH translocations were equally distributed between ploidy groups. We conclude that the interphase fluorescence in situ hybridization–based hyperdiploidy score is also a feasible tool to delineate hyperdiploid patients in early-stage monoclonal gammopathies and that the cytogenetic pathogenetic concepts developed in MM are transferable to AL.

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM): novel biological insights and development of early treatment strategies

Monoclonal gammopathy of unknown significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic plasma cell dyscrasias, with a propensity to progress to symptomatic MM. In recent years there have been improvements in risk stratification models (involving molecular markers) of both disorders, which have led to better understanding of the biology and probability of progression of MGUS and SMM. In the context of numerous molecular events and heterogeneous risk of progression, developing individualized risk profiles for patients with MGUS and SMM represents an ongoing challenge that has to be addressed by prospective clinical monitoring and extensive correlative science. In this review we discuss the current standard of care of patients with MGUS and SMM, the use of risk models, including flow cytometry and free-light chain analyses, for predicting risk of progression. Emerging evidence from molecular studies on MGUS and SMM, involving cytogenetics, gene-expression profiling, and microRNA as well as molecular imaging is described. Finally, future directions for improving individualized management of MGUS and SMM patients, as well as the potential for developing early treatment strategies designed to delay and prevent development of MM are discussed.

From myeloma precursor disease to multiple myeloma: new diagnostic concepts and opportunities for early intervention

Since monoclonal gammopathy of undetermined significance (MGUS) was first described more than 30 years ago, the definition of the entity has evolved. Today, 3 distinct clinical MGUS subtypes have been defined: non-immunoglobulin M (IgM; IgG or IgA) MGUS, IgM MGUS, and light chain MGUS. Each clinical MGUS subtype is characterized by unique intermediate stages and progression events. Although we now have strong evidence that multiple myeloma is consistently preceded by a precursor state at the molecular level, there is urgent need to better understand mechanisms that regulate transformation from precursor to full-blown multiple myeloma. In the future, if such knowledge was available, it would allow clinicians to define high-risk and low-risk precursor patients for a more tailored clinical management. Also, it would provide insights on the individual patient's disease biology, which, in turn, can be used for targeted and more individualized treatment strategies. On the basis of current clinical guidelines, patients diagnosed with MGUS and smoldering myeloma should not be treated outside of clinical trials. In the near future, it seems reasonable to believe that high-risk precursor patients will likely become candidates for early treatment strategies. In this review, we discuss novel insights from recent studies and propose future directions of relevance for clinical management and research studies.

Molecular pathogenesis of multiple myeloma: chromosomal aberrations, changes in gene expression, cytokine networks, and the bone marrow microenvironment

This chapter focuses on two aspects of myeloma pathogenesis: (1) chromosomal aberrations and resulting changes in gene and protein expression with a special focus on growth and survival factors of malignant (and normal) plasma cells and (2) the remodeling of the bone marrow microenvironment induced by accumulating myeloma cells. We begin this chapter with a discussion of normal plasma cell generation, their survival, and a novel class of inhibitory factors. This is crucial for the understanding of multiple myeloma, as several abilities attributed to malignant plasma cells are already present in their normal counterpart, especially the production of survival factors and interaction with the bone marrow microenvironment (niche). The chapter closes with a new model of pathogenesis of myeloma.

Chromosomal aberrations +1q21 and del(17p13) predict survival in patients with recurrent multiple myeloma treated with lenalidomide and dexamethasone

BACKGROUND

In the era of novel agents such as lenalidomide and bortezomib, risk stratification by chromosomal abnormalities may enable a more rational selection of therapeutic approaches in patients with multiple myeloma (MM).

METHODS

The authors analyzed the prognostic value of deletion del(13q14), del(17p13), +1q21, translocation t(4;14), t(11;14), and t(14;16) by fluorescence in situ hybridization (FISH) in a series of 92 patients with recurrent MM who were treated with lenalidomide and dexamethasone (len/dex) at the study center.

RESULTS

Patients carrying del(13q14) or t(14;16) were found to have a shorter median time to disease progression (TTP) of 5.1 months (vs 14.4 months; P = .009) and 2.0 months (vs 10.5 months; P <.001), respectively. However, no effect on TTP was observed in patients harboring del(13q14) as an exclusive chromosomal aberration without the concomitant presence of t(4;14) or del(17p13). The median overall survival (OS) for patients with del(17p13) or +1q21 was 6.7 months (P = .002) and 8.3 months (P < .001), respectively, whereas the median OS for patients carrying none of these abnormalities was not reached. Multivariate analysis revealed that the effects of del(17p13) and +1q21 on OS were independent of patient age as well as the type and number of regimens administered before len/dex.

CONCLUSIONS

The results of the current study suggest that the prognostic significance of t(4;14) may be ameliorated or eliminated in patients treated with len/dex, whereas the presence of del(17p13) or +1q21 is still associated with a dismal OS. The presence of t(11;14) and del(13q14) as exclusive chromosomal aberrations indicates no impact on outcome. Because of its rarity in MM, a confirmation of the prognostic role of the t(14;16) aberration is still pending.

Multiple myeloma precursor disease

Recent data indicate that multiple myeloma is consistently preceded by the precursor states of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma. Currently, multiple myeloma is a clinical diagnosis based on manifestations including hypercalcemia, renal failure, anemia, and bone lesions, whereas MGUS and smoldering myeloma are diagnosed based on laboratory abnormalities. Current clinical markers allow for more individualized risk stratification and counseling of these patients. However, there is a dearth of biomarkers and molecular imaging techniques capable of (1) accurately identifying patients with disease biology corresponding with high risk of progression; (2) elucidating the mechanism of transformation to multiple myeloma; and (3) forming a framework for development of targeted therapies. This case presentation and review discusses the current understanding of myeloma precursor disease and future opportunities for improving personalized management of patients with MGUS or smoldering myeloma, as well as the potential for developing early treatment strategies designed to delay and prevent development of multiple myeloma.

Aberrant global methylation patterns affect the molecular pathogenesis and prognosis of multiple myeloma

We used genome-wide methylation microarrays to analyze differences in CpG methylation patterns in cells relevant to the pathogenesis of myeloma plasma cells (B cells, normal plasma cells, monoclonal gammopathy of undetermined significance [MGUS], presentation myeloma, and plasma cell leukemia). We show that methylation patterns in these cell types are capable of distinguishing nonmalignant from malignant cells and the main reason for this difference is hypomethylation of the genome at the transition from MGUS to presentation myeloma. In addition, gene-specific hypermethylation was evident at the myeloma stage. Differential methylation was also evident at the transition from myeloma to plasma cell leukemia with remethylation of the genome, particularly of genes involved in cell-cell signaling and cell adhesion, which may contribute to independence from the bone marrow microenvironment. There was a high degree of methylation variability within presentation myeloma samples, which was associated with cytogenetic differences between samples. More specifically, we found methylation subgroups were defined by translocations and hyperdiploidy, with t(4;14) myeloma having the greatest impact on DNA methylation. Two groups of hyperdiploid samples were identified, on the basis of unsupervised clustering, which had an impact on overall survival. Overall, DNA methylation changes significantly during disease progression and between cytogenetic subgroups.

The basis and rational use of molecular genetic testing in mature B-cell lymphomas

An increasing number of neoplasms are associated with variably specific genetic abnormalities. This is best exemplified by hematological malignancies, in which there is a growing list of entities that are defined by their genetic lesion(s); this is not (yet) the case in mature B-cell lymphomas. However, enhanced insights into the pathogenesis of this large and diverse group of lymphomas have emerged with the ongoing unraveling of a plethora of fascinating genetic abnormalities. The purpose of this review is to synthesize well-recognized data and nascent discoveries in our understanding of the genetic basis of a spectrum of mature B-cell lymphomas, and how this may be applied to contemporary clinical practice. Despite the explosion of new and exciting knowledge in this arena, with the potential for enhanced diagnostic and prognostic strategies, it is essential to remain cognizant of the limitations (and complexity) of genetic investigations, so that assays can be developed and used both judiciously and rationally.

Smoldering (asymptomatic) multiple myeloma: revisiting the clinical dilemma and looking into the future

Recent studies show that multiple myeloma (MM) is consistently preceded by an asymptomatic precursor state. Smoldering MM (SMM) is a MM precursor defined by an M-protein concentration >or= 3 g/dL and/or >or= 10% bone marrow plasma cells, in the absence of end-organ damage. Compared with individuals diagnosed with monoclonal gammopathy of undetermined significance (MGUS), patients with SMM have a much higher annual risk of developing MM. However, based on clinical observations, the natural history of SMM varies greatly, from stable MGUS-like disease to highly progressive disease. Using conventional clinical markers, SMM patients can be stratified into 3 risk groups. Importantly, because of considerable molecular heterogeneity, we currently lack reliable markers to predict prognosis for individual SMM patients. Furthermore, until recently, potent drugs with reasonable toxicity profiles have not been available for the development of early MM treatment strategies. Consequently, current clinical guidelines emphasize the application of close clinical monitoring followed by treatment when the patient develops symptomatic MM. This review focuses on novel biomarkers, molecular profiles, and microenvironmental interactions of interest in myelomagenesis. We also discuss how the integration of novel biologic markers and clinical monitoring of SMM could facilitate the development of early treatment strategies for high-risk SMM patients in the future.

A compendium of myeloma-associated chromosomal copy number abnormalities and their prognostic value

To obtain a comprehensive genomic profile of presenting multiple myeloma cases we performed high-resolution single nucleotide polymorphism mapping array analysis in 114 samples alongside 258 samples analyzed by U133 Plus 2.0 expression array (Affymetrix). We examined DNA copy number alterations and loss of heterozygosity (LOH) to define the spectrum of minimally deleted regions in which relevant genes of interest can be found. The most frequent deletions are located at 1p (30%), 6q (33%), 8p (25%), 12p (15%), 13q (59%), 14q (39%), 16q (35%), 17p (7%), 20 (12%), and 22 (18%). In addition, copy number-neutral LOH, or uniparental disomy, was also prevalent on 1q (8%), 16q (9%), and X (20%), and was associated with regions of gain and loss. Based on fluorescence in situ hybridization and expression quartile analysis, genes of prognostic importance were found to be located at 1p (FAF1, CDKN2C), 1q (ANP32E), and 17p (TP53). In addition, we identified common homozygously deleted genes that have functions relevant to myeloma biology. Taken together, these analyses indicate that the crucial pathways in myeloma pathogenesis include the nuclear factor-κB pathway, apoptosis, cell-cycle regulation, Wnt signaling, and histone modifications. This study was registered at http://isrctn.org as ISRCTN68454111.

The t(14;20) is a poor prognostic factor in myeloma but is associated with long-term stable disease in monoclonal gammopathies of undetermined significance

A large series of plasma cell dyscrasias (n=2207) was examined for translocations which deregulate the MAF genes, t(14;20)(q32;q12) and t(14;16)(q32;q23), and their disease behavior was compared to a group characterized by the t(4;14)(p16;q32) where CCND2 is also up-regulated. The t(14;20) showed low prevalence in myeloma (27/1830, 1.5%) and smoldering myeloma (1/148, <1%) with a higher incidence in MGUS (9/193, 5% P=0.005). Strong associations with del(13) (76%), non-hyperdiploidy (83%) and gain of 1q (58%) were seen but no association with an IgA M-protein or absence of bone disease was noted. All three translocations were associated with poor outcome in myeloma, but strikingly all t(14;20) MGUS/smoldering myeloma cases (n=10) had stable, low level disease. In contrast, the 10 t(14;16) and 25 t(4;14) MGUS/smoldering myeloma cases were associated with both evolving and non-evolving disease. None of the associated genetic abnormalities helped to predict for progression from MGUS or smoldering myeloma.

Combining information regarding chromosomal aberrations t(4;14) and del(17p13) with the International Staging System classification allows stratification of myeloma patients undergoing autologous stem cell transplantation

BACKGROUND

Chromosomal abnormalities have been shown to play a major role in disease evolution of multiple myeloma. Specific changes in interphase cells can be detected by fluorescent in situ hybridization, which overcomes the problem of the lack of dividing cells required for conventional cytogenetics.

DESIGN AND METHODS

We analyzed the prognostic value of 12 frequent chromosomal abnormalities detected by fluorescent in situ hybridization in a series of patients (n=315) with newly diagnosed, symptomatic multiple myeloma. All patients underwent frontline autologous stem cell transplantation according to the GMMG-HD3- or GMMG-HD4-trial protocols or analogous protocols.

RESULTS

Univariate statistical analyses revealed that the presence of del(13q14), del(17p13), t(4;14), +1q21 and non-hyperdiploidy was associated with adverse progression-free and overall survival rates independently of the International Staging System (ISS) classification. Multivariate analyses showed that only t(4;14) and del(17p13) retained prognostic value for both progression-free and overall survival. According to the presence or absence of t(4;14) and del(17p13) and the patients' International Staging System classification, the cohort could be stratified into three distinct groups: a group with a favorable prognosis [absence of t(4;14)/del(17p13) and ISS I], a group with a poor prognosis [presence of t(4;14)/del(17p13) and ISS II/III] and a group with an intermediate prognosis (all remaining patients). The probabilities of overall survival at 5 years decreased from 72% in the favorable prognostic group to 62% (hazard ratio 2.4; P=0.01) in the intermediate and 41% (hazard ratio 5.6; P<0.001) in the poor prognostic groups.

CONCLUSIONS

These results have implications for risk-adapted management for patients with multiple myeloma undergoing high-dose chemotherapy followed by autologous stem cell transplantation and suggest that new treatment concepts are urgently needed for patients who belong to the poor prognosis group. As targeted therapies evolve, different treatment options might have variable success, depending on the underlying genetic nature of the clone.

Timing of acquisition of deletion 13 in plasma cell dyscrasias is dependent on genetic context

BACKGROUND

Multiple myeloma, monoclonal gammopathy of undetermined significance and smoldering multiple myeloma harbor common chromosomal abnormalities but the prevalence and relative association of aberrations in these diagnostic groups remains controversial. We investigated these aspects in a large series of patients.

DESIGN AND METHODS

Chromosome 13 deletion (Delta13), deletion of TP53, ploidy status and immunoglobulin heavy chain (IgH) translocations were evaluated by fluorescence in situ hybridization in patients with monoclonal gammopathy of undetermined significance (n=189), smoldering multiple myeloma (n=127) and multiple myeloma (n=400).

RESULTS

Overall, Delta13 (25%, 34% and 47%), 16q23 deletions (6%, 8% and 21%) and 17p13 deletions (3%, 1% and 10%) were less frequent in patients with monoclonal gammopathy of undetermined significance and smoldering multiple myeloma than in those with multiple myeloma. When distinct genetic groups were considered, no differences in the prevalence of Delta13 were found with t(4;14)(p16;q32) and t(14;16)(q32;q23) among the three diagnostic groups; in contrast Delta13 was rarer in t(11;14)(q13;q32) in patients with monoclonal gammopathy (1/28) and smoldering myeloma (2/13) than in those with multiple myeloma (40%). Similar results were seen for the few t(6;14)(p21;q32) cases: 0/3 patients with monoclonal gammopathy or smoldering myeloma had the Delta13, whereas 4/6 (67%) patients with multiple myeloma and this translocation also had the deletion. In multiple myeloma patients with both an IgH translocation and Delta13, the proportions of cells affected by the two abnormalities were similar, as was the case for t(4;14) and t(14;16) monoclonal gammopathy patients positive for Delta13. In contrast, in monoclonal gammopathy patients with t(14;20)(q32;q11), the translocation was present in almost all cells, while the Delta13 was present in only a sub-population.

CONCLUSIONS

These results indicate that the presence and time of occurrence of Delta13 depends on the presence of specific concurrent abnormalities. The observation that Delta13 was extremely rare in monoclonal gammopathy of undetermined significance and smoldering multiple myeloma with translocations directly involving cyclin D genes (CCND1 and CCND3) suggest a possible role of Delta13 in the progression of the disease specifically in these genetic sub-groups. (clinicaltrials.gov identifier: ISRCTN 68454111; UKCRN ID 1176).

Micro-RNA-15a and micro-RNA-16 expression and chromosome 13 deletions in multiple myeloma

We have used copy number variation (CNV) analysis with SNP mapping arrays for miRNA-15a and miRNA-16-1 expression analysis in patients with multiple myeloma (MM) with or without deletion of chromosome 13q14. MiRNA-15a and miRNA-16 display a range of expression patterns in MM patients, independent of the chromosome 13 status. These findings suggest that genes other than miR-15a and miR-16 may explain the prognostic significance of 13q14 deletions.

Bortezomib, thalidomide, dexamethasone induction therapy followed by melphalan, prednisolone, thalidomide consolidation therapy as a first line of treatment for patients with multiple myeloma who are non-transplant candidates: results of the Korean Multiple Myeloma Working Party (KMMWP)

Bortezomib (VELCADE), thalidomide and dexamethasone (VTD), as well as melphalan, prednisolone, and thalidomide (MPT) therapy, are highly effective in patients with multiple myeloma. We evaluated the responses and survival times of 35 patients treated with VTD followed by MPT. All patients were newly diagnosed and non-transplantation candidates. Patients received six cycles of VTD, which were followed by eight cycles of MPT. Approximately 97% of patients exhibited early responses to therapy, as early as the second cycle of VTD. Thirty percent of the responses were high quality, which was defined as a complete response (CR), a near-CR or a very good partial response. High-risk patients were defined as patients with any of the following aberrations: del(13), t(4;14), or del(17p). The remaining patients were defined as standard risk. Eleven high-risk patients showed 100% response rates, including 91% high-quality responses. In contrast, 13 standard-risk patients exhibited 92% response rates, including 61% high-quality responses. The overall 2-year survival rates were 60% in high-risk patients and 85% in standard-risk patients, which was not significantly different. As a first-line therapy, VTD followed by MPT has the potential to provide high-quality responses with durable remission among elderly and high-risk patients (clinicaltrials.gov identifier: NCT00320476).

Management of newly diagnosed symptomatic multiple myeloma: updated Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus guidelines

Multiple myeloma is a malignant plasma cell neoplasm that affects more than 20,000 people each year and is the second most common hematologic malignancy. It is part of a spectrum of monoclonal plasma cell disorders, many of which do not require active therapy. During the past decade, considerable progress has been made in our understanding of the disease process and factors that influence outcome, along with development of new drugs that are highly effective in controlling the disease and prolonging survival without compromising quality of life. Identification of well-defined and reproducible prognostic factors and introduction of new therapies with unique modes of action and impact on disease outcome have for the first time opened up the opportunity to develop risk-adapted strategies for managing this disease. Although these risk-adapted strategies have not been prospectively validated, enough evidence can be gathered from existing randomized trials, subgroup analyses, and retrospective studies to develop a working framework. This set of recommendations represents such an effort-the development of a set of consensus guidelines by a group of experts to manage patients with newly diagnosed disease based on an interpretation of the best available evidence.

Frequent upregulation of MYC in plasma cell leukemia

Plasma cell leukemia (PCL) is a rare form of monoclonal gammopathy, which can originate de novo or evolve from multiple myeloma (MM) as a terminal leukemic phase. Previous cytogenetic studies of PCL have reported the presence of complex karyotypes with involvement of multiple unidentified chromosomal regions. We report here the analysis of 12 PCL (10 primary and two secondary) by metaphase and FISH analysis combined with oligonucleotide array data (244 k, Agilent). Interphase-FISH results were compared with those from a series of 861 newly diagnosed patients with MM. Cytogenetic analysis was successful on 11 patients, all of whom showed clonal chromosomal abnormalities. Compared with MM, t(11;14)(q13;q32) (42% versus 15%; P = 0.027) and t(14;16)(q32;q23) (25% versus 4%; P = 0.010) were more frequent in PCL, although neither the specific partner chromosome involved in the IgH translocation nor the ploidy status predicted for survival. Chromosomes 1, 8, 13, and 16 showed the highest number of copy number alterations with 8q24 being the chromosomal region most frequently involved. In eight of 12 patients we found abnormalities (translocations, one amplification, small deletions, and duplications) that directly targeted or were very close to MYC. Only four of these changes were detected by routine FISH analysis using commercial probes with the others exclusively detected by arrays. Quantitative reverse transcription polymerase chain reaction demonstrated that these different abnormalities were associated with increased levels of MYC mRNA. We conclude that MYC dysregulation by complex mechanisms is one of the major molecular events in the oncogenesis of PCL.

International Myeloma Working Group molecular classification of multiple myeloma: spotlight review

Myeloma is a malignant proliferation of monoclonal plasma cells. Although morphologically similar, several subtypes of the disease have been identified at the genetic and molecular level. These genetic subtypes are associated with unique clinicopathological features and dissimilar outcome. At the top hierarchical level, myeloma can be divided into hyperdiploid and non-hyperdiploid subtypes. The latter is mainly composed of cases harboring IgH translocations, generally associated with more aggressive clinical features and shorter survival. The three main IgH translocations in myeloma are the t(11;14)(q13;q32), t(4;14)(p16;q32) and t(14;16)(q32;q23). Trisomies and a more indolent form of the disease characterize hyperdiploid myeloma. A number of genetic progression factors have been identified including deletions of chromosomes 13 and 17 and abnormalities of chromosome 1 (1p deletion and 1q amplification). Other key drivers of cell survival and proliferation have also been identified such as nuclear factor- B-activating mutations and other deregulation factors for the cyclin-dependent pathways regulators. Further understanding of the biological subtypes of the disease has come from the application of novel techniques such as gene expression profiling and array-based comparative genomic hybridization. The combination of data arising from these studies and that previously elucidated through other mechanisms allows for most myeloma cases to be classified under one of several genetic subtypes. This paper proposes a framework for the classification of myeloma subtypes and provides recommendations for genetic testing. This group proposes that genetic testing needs to be incorporated into daily clinical practice and also as an essential component of all ongoing and future clinical trials.

Plasma cell myeloma

Plasma cell myeloma is a heterogenous disease with variable clinical presentation and outcome. The prognosis is largely determined by tumor biology. Newer therapeutic agents are rapidly changing the survival outlook of myeloma patients.

Staging systems and prognostic factors as a guide to therapeutic decisions in multiple myeloma

Multiple myeloma (MM) patients have a highly variable disease course and survival varies from a few months to more than 10 years. Numerous prognostic factors have been identified, including age, performance status (PS), serum albumin, beta2-microglobulin (beta2M), lactate dehydrogenase (LDH), renal function, genetic factors, and serum free light chains (sFLCs) or their ratio (sFLCR). Several models have been built to separate patients into various risk groups with different outcomes. Staging systems need to be simple, accurate, and readily available in order to effectively guide treatment decisions now that effective treatments exist that prolong survival. The International Staging System (ISS) is currently in use; it is highly prognostic but presents some limitations. We suggest that the ISS prognostic potential could be improved with the addition of sFLCR and eventually LDH.

Relevant prognostic features of multiple myeloma and the new International Staging System

The new International Staging System should be reported in all future studies of multiple myeloma. However, the system fails to account for recent research findings pertaining to mechanisms of disease progression. This review describes development of the International Staging System and details prognostic factors that may further our understanding of the biology of multiple myeloma.

Loss of 1p and rearrangement of MYC are associated with progression of smouldering myeloma to myeloma: sequential analysis of a single case

We report serial genetic studies on a young female patient initially diagnosed with asymptomatic smouldering myeloma who progressed to symptomatic myeloma 4.5 years after presentation. An unbalanced translocation, der(14)t(4;14)(p16;q32), was initially found in all plasma cells plus deletions of other chromosomal regions as detected by array-based comparative genomic hybridization. Deletion of chromosome 13 was observed in a minor population of plasma cells (<20%) for the first two years, increasing to 100% of plasma cells by the time of multiple myeloma diagnosis. Loss of 1p and a rearrangement of MYC were first observed in a small population of plasma cells one year prior to the clinical diagnosis of multiple myeloma, but these subclones increased rapidly in size to become the major population suggesting that they were directly involved in the transformation process. This case report provides a unique insight into the mechanisms of disease progression from smouldering multiple myeloma to multiple myeloma.

New generation pharmacotherapy in elderly multiple myeloma patients

BACKGROUND

Observational databases have demonstrated that the overall prognosis of multiple myeloma patients has markedly improved over the past decade, yet the greatest strides have been attained in younger rather than older patients.

OBJECTIVE

To review recent clinical trials that include new generation agents (thalidomide, lenalidomide and bortezomib) and autologous stem cell transplantation in older multiple myeloma patients.

RESULTS

Conventional regimens such as melphalan plus prednisone can be improved with the addition of thalidomide or bortezomib: more patients attain complete and near-complete remission, and progression-free survival rates are nearly doubled. In addition, autologous hematopoietic stem cell transplantation studies show that this treatment approach can be used successfully in selected older myeloma patients in whom the toxicity profile of autotransplant and resulting overall survival may be similar to that obtained in the younger patient group.

CONCLUSIONS

In the advanced-age population, implementation of new therapies results in significant benefits in older as well as younger patients.

Interphase FISH in plasma cell dyscrasia: increase in abnormality detection with plasma cell enrichment

Historically, cytogenetic studies of plasma cell neoplasms have been hampered by the fact that terminally differentiated plasma cells do not proliferate well in vitro. Although the use of interphase FISH (iFISH) has greatly improved the ability to detect cytogenetic abnormalities, cases with low numbers of neoplastic cells often do not demonstrate abnormalities. Using a four-assay, nine-probe iFISH panel, we compared the abnormality detection rate for overnight unstimulated bone marrow cultures (ONC) to that for plasma-cell enriched fractions obtained with use of CD138-coated immunomagnetic beads (PCE). In the ONC, an abnormality was detected in 11 of 29 cases (38%); in the PCE, an abnormality was detected in 30 of 33 cases (91%). For 28 cases in which iFISH results from ONC were compared directly with PCE samples, the overall abnormality rate was 36% for ONC and 89% for PCE (P < 0.01). The conventional GTG-banded chromosome analysis revealed only 2 of 34 cases with an abnormal karyotype (6%); both cases were hyperdiploid. We conclude that the plasma cell enrichment step for iFISH should be incorporated into the routine cytogenetic work-up for all patients with plasma cell neoplasms.

Neurobeachin (NBEA) is a target of recurrent interstitial deletions at 13q13 in patients with MGUS and multiple myeloma

OBJECTIVE

Chromosome 13 deletions (del[13]), detected by metaphase cytogenetics, predict poor outcomes in multiple myeloma (MM), but the gene(s) responsible have not been conclusively identified. We sought to identify tumor-suppressor genes on chromosome 13 using a novel array comparative genomic hybridization (aCGH) strategy.

MATERIALS AND METHODS

We identified DNA copy number losses on chromosome 13 using genomic DNA isolated from CD138-enriched bone marrow cells (tumor) from 20 patients with MM, monoclonal gammopathy of undetermined significance, or amyloidosis. We used matched skin biopsy (germline) genomic DNA to control for copy number polymorphisms and a novel aCGH array dedicated to chromosome 13 to map somatic DNA gains and losses at ultra-high resolution (>385,000 probes; median probe spacing 60 bp). We analyzed microarray expression data from an additional 262 patient samples both with and without del[13].

RESULTS

Two distinct minimally deleted regions at 13q14 and 13q13 were defined that affected the RB1 and NBEA genes, respectively. RB1 is a canonical tumor suppressor previously implicated in MM. NBEA is implicated in membrane trafficking in neurons, protein kinase A binding, and has no known role in cancer. Noncoding RNAs on chromosome 13 were not affected by interstitial deletions. Both the RB1 and NBEA genes were deleted in 40% of cases (8 of 20; 5 patients with del[13] detected by traditional methods and 3 patients with interstitial deletions detected by aCGH). Forty-one additional MM patient samples were used for complete exonic sequencing of RB1, but no somatic mutations were found. Along with RB1, NBEA gene expression was significantly reduced in cases with del[13].

CONCLUSIONS

The NBEA gene at 13q13, and its expression are frequently disrupted in MM. Additional studies are warranted to evaluate the role of NBEA as a novel candidate tumor-suppressor gene.

Deletions of CDKN2C in multiple myeloma: biological and clinical implications

PURPOSE

Deletions of chromosome 1 have been described in 7% to 40% of cases of myeloma with inconsistent clinical consequences. CDKN2C at 1p32.3 has been identified in myeloma cell lines as the potential target of the deletion. We tested the clinical impact of 1p deletion and used high-resolution techniques to define the role of CDKN2C in primary patient material.

EXPERIMENTAL DESIGN

We analyzed 515 cases of monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and newly diagnosed multiple myeloma using fluorescence in situ hybridization (FISH) for deletions of CDKN2C. In 78 myeloma cases, we carried out Affymetrix single nucleotide polymorphism mapping and U133 Plus 2.0 expression arrays. In addition, we did mutation, methylation, and Western blotting analysis.

RESULTS

By FISH we identified deletion of 1p32.3 (CDKN2C) in 3 of 66 MGUS (4.5%), 4 of 39 SMM (10.3%), and 55 of 369 multiple myeloma cases (15%). We examined the impact of copy number change at CDKN2C on overall survival (OS), and found that the cases with either hemizygous or homozygous deletion of CDKN2C had a worse OS compared with cases that were intact at this region (22 months versus 38 months; P = 0.003). Using gene mapping we identified three homozygous deletions at 1p32.3, containing CDKN2C, all of which lacked expression of CDKN2C. Cases with homozygous deletions of CDKN2C were the most proliferative myelomas, defined by an expression-based proliferation index, consistent with its biological function as a cyclin-dependent kinase inhibitor.

CONCLUSIONS

Our results suggest that deletions of CDKN2C are important in the progression and clinical outcome of myeloma.

Association between renal cell carcinoma and plasma cell dyscrasias: a case series of six patients

Multiple malignancies in the same patient are unusual. This is particularly true for patients with hematologic malignancies who have a concomitant solid tumor. We report the unexpectedly higher frequency of renal cell carcinoma (RCC) associated with plasma cell dyscrasias. We report 6 cases of RCC in our institutional database of 600 patients with plasma cell dyscrasias over the past 10 years. We discuss the possible mechanisms that predisposed these patients to a secondary malignancy.

IgM myeloma: a rare entity characterized by a CD20-CD56-CD117- immunophenotype and the t(11;14)

IgM myeloma is a very rare and poorly defined entity. In a detailed assessment of 10 cases, it was demonstrated that 70% had an aberrant phenotype based on the expression of CD19, CD45, CD27 and Cyclin D1 but all cases lacked CD56 and CD117. Interphase fluorescence in situ hybridization demonstrated deletion 13 in 50% while 5/8 cases assessed had a t(11;14). Despite the high incidence of the t(11;14), CD20 was only expressed in one of nine cases. We conclude that IgM myeloma is a distinctive subset characterized by a CD20-CD56-CD117- phenotype and the t(11;14).

Role of genetics in prognostication in myeloma

As in other hematological malignancies, cytogenetics is becoming a major prognostic parameter in myeloma. Myeloma differs from other hemopathies particularly in technical aspects related to low proliferation and partial infiltrates. Thus, fluorescence in-situ hybridization (FISH) is probably the best method for cytogenetic assessment in myeloma, but it requires the identification of the malignant cells (morphologically, immunologically or through sorting). Several chromosomal abnormalities have been identified. Among them, the t(4;14) and t(14;16) translocations and the del(17p) are the most important for outcome prediction, all of them predicting a short overall survival. However, even in these genetically defined subgroups, an outcome heterogeneity is observed, suggesting the role of other factors (genetic or otherwise) in disease evolution.